diff --git a/src/components/dialogs/limits/limits-pane-utils.ts b/src/components/dialogs/limits/limits-pane-utils.ts
index dc6bcb8029..d37ec23922 100644
--- a/src/components/dialogs/limits/limits-pane-utils.ts
+++ b/src/components/dialogs/limits/limits-pane-utils.ts
@@ -36,6 +36,7 @@ import {
     AttributeModification,
     CurrentLimits,
     OperationalLimitsGroup,
+    OperationalLimitsGroupModificationInfos,
     OperationType,
     TemporaryLimit,
 } from '../../../services/network-modification-types';
@@ -142,6 +143,8 @@ const limitsValidationSchemaCreation = (id: string) => {
     return { [id]: yup.object().shape(completeLimitsGroupSchema) };
 };
 
+export type LimitsFormSchema = yup.InferType<ReturnType<typeof limitsValidationSchemaCreation>[typeof LIMITS]>;
+
 export const getLimitsValidationSchema = (id: string = LIMITS) => {
     return limitsValidationSchemaCreation(id);
 };
@@ -162,7 +165,7 @@ export const getLimitsEmptyFormData = (isModification = true, id = LIMITS) => {
 };
 
 export const formatOpLimitGroupsToFormInfos = (
-    limitGroups: OperationalLimitsGroup[]
+    limitGroups?: OperationalLimitsGroup[] | OperationalLimitsGroupModificationInfos[] | null
 ): OperationalLimitsGroupFormSchema[] => {
     if (!limitGroups) {
         return [];
@@ -170,23 +173,23 @@ export const formatOpLimitGroupsToFormInfos = (
 
     return limitGroups
         .filter(
-            (opLimitGroup: OperationalLimitsGroup) =>
+            (opLimitGroup: OperationalLimitsGroup | OperationalLimitsGroupModificationInfos) =>
                 opLimitGroup.modificationType !== LIMIT_SETS_MODIFICATION_TYPE.DELETE
         )
-        .map((opLimitGroup: OperationalLimitsGroup) => {
+        .map((opLimitGroup: OperationalLimitsGroup | OperationalLimitsGroupModificationInfos) => {
             return {
                 id: opLimitGroup.id + opLimitGroup.applicability,
                 name: opLimitGroup.id,
                 applicability: opLimitGroup.applicability,
                 limitsProperties: opLimitGroup.limitsProperties,
                 currentLimits: {
-                    permanentLimit: opLimitGroup.currentLimits.permanentLimit,
+                    permanentLimit: opLimitGroup?.currentLimits?.permanentLimit,
                     temporaryLimits: formatTemporaryLimitsModificationToFormSchema(
-                        opLimitGroup.currentLimits.temporaryLimits
+                        opLimitGroup?.currentLimits?.temporaryLimits as TemporaryLimit[]
                     ),
                 },
             };
-        });
+        }) as OperationalLimitsGroupFormSchema[];
 };
 
 export const getAllLimitsFormData = (
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/characteristics-pane/two-windings-transformer-characteristics-pane-utils.js b/src/components/dialogs/network-modifications/two-windings-transformer/characteristics-pane/two-windings-transformer-characteristics-pane-utils.ts
similarity index 80%
rename from src/components/dialogs/network-modifications/two-windings-transformer/characteristics-pane/two-windings-transformer-characteristics-pane-utils.js
rename to src/components/dialogs/network-modifications/two-windings-transformer/characteristics-pane/two-windings-transformer-characteristics-pane-utils.ts
index 8b60a92bbe..4b6e54cc90 100644
--- a/src/components/dialogs/network-modifications/two-windings-transformer/characteristics-pane/two-windings-transformer-characteristics-pane-utils.js
+++ b/src/components/dialogs/network-modifications/two-windings-transformer/characteristics-pane/two-windings-transformer-characteristics-pane-utils.ts
@@ -7,8 +7,12 @@
 
 import { CHARACTERISTICS, G, B, RATED_S, RATED_U1, RATED_U2, R, X } from 'components/utils/field-constants';
 import yup from 'components/utils/yup-config';
+import { CharacteristicsFormSchema } from '../two-windings-transformer.types';
 
-const characteristicsValidationSchema = (isModification, additionalFields) => ({
+type AdditionalValidationFields = Record<string, yup.AnySchema>;
+type AdditionalDataFields = Record<string, unknown>;
+
+const characteristicsValidationSchema = (isModification: boolean, additionalFields: AdditionalValidationFields) => ({
     [CHARACTERISTICS]: yup.object().shape({
         [R]: isModification
             ? yup.number().nullable().min(0, 'mustBeGreaterOrEqualToZero')
@@ -33,7 +37,7 @@ export const getCharacteristicsValidationSchema = (isModification = false, addit
     return characteristicsValidationSchema(isModification, additionalFields);
 };
 
-const characteristicsEmptyFormData = (additionalFields) => ({
+const characteristicsEmptyFormData = (additionalFields: AdditionalDataFields) => ({
     [CHARACTERISTICS]: {
         [R]: null,
         [X]: null,
@@ -51,7 +55,15 @@ export const getCharacteristicsEmptyFormData = (additionalFields = {}) => {
 };
 
 export const getCharacteristicsFormData = (
-    { r = null, x = null, g = null, b = null, ratedS = null, ratedU1 = null, ratedU2 = null },
+    {
+        r = null,
+        x = null,
+        g = null,
+        b = null,
+        ratedS = null,
+        ratedU1 = null,
+        ratedU2 = null,
+    }: CharacteristicsFormSchema,
     additionalFields = {}
 ) => {
     return {
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/characteristics-pane/two-windings-transformer-characteristics-pane.jsx b/src/components/dialogs/network-modifications/two-windings-transformer/characteristics-pane/two-windings-transformer-characteristics-pane.tsx
similarity index 90%
rename from src/components/dialogs/network-modifications/two-windings-transformer/characteristics-pane/two-windings-transformer-characteristics-pane.jsx
rename to src/components/dialogs/network-modifications/two-windings-transformer/characteristics-pane/two-windings-transformer-characteristics-pane.tsx
index fdafc4aace..d45781e84e 100644
--- a/src/components/dialogs/network-modifications/two-windings-transformer/characteristics-pane/two-windings-transformer-characteristics-pane.jsx
+++ b/src/components/dialogs/network-modifications/two-windings-transformer/characteristics-pane/two-windings-transformer-characteristics-pane.tsx
@@ -19,9 +19,20 @@ import { Grid } from '@mui/material';
 import { B, CHARACTERISTICS, G, R, RATED_S, RATED_U1, RATED_U2, X } from 'components/utils/field-constants';
 import { FormattedMessage } from 'react-intl';
 import GridItem from '../../../commons/grid-item';
+import { TwoWindingsTransformerMapInfos } from '../two-windings-transformer.types';
 import GridSection from '../../../commons/grid-section';
 
-const TwoWindingsTransformerCharacteristicsPane = ({ id = CHARACTERISTICS, twtToModify, isModification = false }) => {
+export interface TwoWindingsTransformerCharacteristicsPaneProps {
+    id?: string;
+    twtToModify?: TwoWindingsTransformerMapInfos | null;
+    isModification?: boolean;
+}
+
+const TwoWindingsTransformerCharacteristicsPane = ({
+    id = CHARACTERISTICS,
+    twtToModify,
+    isModification = false,
+}: TwoWindingsTransformerCharacteristicsPaneProps) => {
     const width = isModification ? 12 : 8;
 
     const seriesResistanceField = (
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/creation/characteristics-pane/two-windings-transformer-creation-characteristics-pane-utils.js b/src/components/dialogs/network-modifications/two-windings-transformer/creation/characteristics-pane/two-windings-transformer-creation-characteristics-pane-utils.ts
similarity index 90%
rename from src/components/dialogs/network-modifications/two-windings-transformer/creation/characteristics-pane/two-windings-transformer-creation-characteristics-pane-utils.js
rename to src/components/dialogs/network-modifications/two-windings-transformer/creation/characteristics-pane/two-windings-transformer-creation-characteristics-pane-utils.ts
index d97ba4c2f4..58f208202a 100644
--- a/src/components/dialogs/network-modifications/two-windings-transformer/creation/characteristics-pane/two-windings-transformer-creation-characteristics-pane-utils.js
+++ b/src/components/dialogs/network-modifications/two-windings-transformer/creation/characteristics-pane/two-windings-transformer-creation-characteristics-pane-utils.ts
@@ -15,6 +15,7 @@ import {
     getCharacteristicsFormData,
     getCharacteristicsValidationSchema,
 } from '../../characteristics-pane/two-windings-transformer-characteristics-pane-utils';
+import { CharacteristicsFormSchema } from '../../two-windings-transformer.types';
 
 const twoWindingsTransformerValidationSchema = () =>
     getCharacteristicsValidationSchema(false, {
@@ -46,6 +47,9 @@ export const getTwoWindingsTransformerFormData = ({
     ratedU2 = null,
     connectivity1 = null,
     connectivity2 = null,
+}: CharacteristicsFormSchema & {
+    connectivity1?: Record<string, unknown> | null;
+    connectivity2?: Record<string, unknown> | null;
 }) =>
     getCharacteristicsFormData(
         {
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/creation/characteristics-pane/two-windings-transformer-creation-characteristics-pane.jsx b/src/components/dialogs/network-modifications/two-windings-transformer/creation/characteristics-pane/two-windings-transformer-creation-characteristics-pane.tsx
similarity index 88%
rename from src/components/dialogs/network-modifications/two-windings-transformer/creation/characteristics-pane/two-windings-transformer-creation-characteristics-pane.jsx
rename to src/components/dialogs/network-modifications/two-windings-transformer/creation/characteristics-pane/two-windings-transformer-creation-characteristics-pane.tsx
index 218dc2fc5e..efd7dbc4db 100644
--- a/src/components/dialogs/network-modifications/two-windings-transformer/creation/characteristics-pane/two-windings-transformer-creation-characteristics-pane.jsx
+++ b/src/components/dialogs/network-modifications/two-windings-transformer/creation/characteristics-pane/two-windings-transformer-creation-characteristics-pane.tsx
@@ -15,7 +15,9 @@ import useVoltageLevelsListInfos from '../../../../../../hooks/use-voltage-level
 import GridSection from '../../../../commons/grid-section';
 import GridItem from '../../../../commons/grid-item';
 import { TwoWindingsTransformerCreationDialogTab } from '../../two-windings-transformer-utils';
-import { LimitsPane } from '../../../../limits/limits-pane.tsx';
+import { LimitsPane } from '../../../../limits/limits-pane';
+import { UUID } from 'node:crypto';
+import { CurrentTreeNode } from 'components/graph/tree-node.type';
 
 const styles = {
     h3: {
@@ -25,13 +27,21 @@ const styles = {
     },
 };
 
+export interface TwoWindingsTransformerCreationCharacteristicsPaneProps {
+    id?: string;
+    studyUuid: UUID;
+    currentNode: CurrentTreeNode;
+    currentRootNetworkUuid: UUID;
+    tabIndex: number;
+}
+
 const TwoWindingsTransformerCreationCharacteristicsPane = ({
     id = CHARACTERISTICS,
     studyUuid,
     currentNode,
     currentRootNetworkUuid,
     tabIndex,
-}) => {
+}: TwoWindingsTransformerCreationCharacteristicsPaneProps) => {
     const voltageLevelOptions = useVoltageLevelsListInfos(studyUuid, currentNode?.id, currentRootNetworkUuid);
     const connectivity1Field = (
         <ConnectivityForm
@@ -59,7 +69,7 @@ const TwoWindingsTransformerCreationCharacteristicsPane = ({
         <>
             <Box hidden={tabIndex !== TwoWindingsTransformerCreationDialogTab.CHARACTERISTICS_TAB} p={1}>
                 <GridSection title="Connectivity" customStyle={styles.h3} />
-                <GridSection title="Side1" heading={4} size="6" />
+                <GridSection title="Side1" heading={4} size={6} />
                 <Grid container spacing={2}>
                     <Grid item container direction="column">
                         <Grid container direction="column" spacing={2}>
@@ -67,7 +77,7 @@ const TwoWindingsTransformerCreationCharacteristicsPane = ({
                         </Grid>
                     </Grid>
                 </Grid>
-                <GridSection title="Side2" heading={4} size="6" />
+                <GridSection title="Side2" heading={4} size={6} />
                 <Grid container spacing={2}>
                     <Grid item container>
                         <Grid container direction="column" spacing={2}>
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/creation/two-windings-transformer-creation-dialog-header.jsx b/src/components/dialogs/network-modifications/two-windings-transformer/creation/two-windings-transformer-creation-dialog-header.tsx
similarity index 100%
rename from src/components/dialogs/network-modifications/two-windings-transformer/creation/two-windings-transformer-creation-dialog-header.jsx
rename to src/components/dialogs/network-modifications/two-windings-transformer/creation/two-windings-transformer-creation-dialog-header.tsx
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/creation/two-windings-transformer-creation-dialog-tabs.jsx b/src/components/dialogs/network-modifications/two-windings-transformer/creation/two-windings-transformer-creation-dialog-tabs.tsx
similarity index 83%
rename from src/components/dialogs/network-modifications/two-windings-transformer/creation/two-windings-transformer-creation-dialog-tabs.jsx
rename to src/components/dialogs/network-modifications/two-windings-transformer/creation/two-windings-transformer-creation-dialog-tabs.tsx
index 91c0610436..58b0c401c6 100644
--- a/src/components/dialogs/network-modifications/two-windings-transformer/creation/two-windings-transformer-creation-dialog-tabs.jsx
+++ b/src/components/dialogs/network-modifications/two-windings-transformer/creation/two-windings-transformer-creation-dialog-tabs.tsx
@@ -5,14 +5,27 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-import { Grid, Tab, Tabs } from '@mui/material';
+import { Breakpoint, Grid, Tab, Tabs } from '@mui/material';
 import { FormattedMessage } from 'react-intl';
 import { useWatch } from 'react-hook-form';
 import { ENABLED, PHASE_TAP_CHANGER, RATIO_TAP_CHANGER } from 'components/utils/field-constants';
 import { getTabIndicatorStyle, getTabStyle } from '../../../../utils/tab-utils';
 import { TwoWindingsTransformerCreationDialogTab } from '../two-windings-transformer-utils';
+import { Dispatch, SetStateAction } from 'react';
 
-const TwoWindingsTransformerCreationDialogTabs = ({ tabIndex, tabIndexesWithError, setTabIndex, setDialogWidth }) => {
+export interface TwoWindingsTransformerCreationDialogTabsProps {
+    tabIndex: number;
+    tabIndexesWithError: number[];
+    setTabIndex: Dispatch<SetStateAction<number>>;
+    setDialogWidth: Dispatch<SetStateAction<Breakpoint>>;
+}
+
+const TwoWindingsTransformerCreationDialogTabs = ({
+    tabIndex,
+    tabIndexesWithError,
+    setTabIndex,
+    setDialogWidth,
+}: TwoWindingsTransformerCreationDialogTabsProps) => {
     const ratioTapChangerEnabledWatch = useWatch({
         name: `${RATIO_TAP_CHANGER}.${ENABLED}`,
     });
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/creation/two-windings-transformer-creation-dialog.jsx b/src/components/dialogs/network-modifications/two-windings-transformer/creation/two-windings-transformer-creation-dialog.tsx
similarity index 70%
rename from src/components/dialogs/network-modifications/two-windings-transformer/creation/two-windings-transformer-creation-dialog.jsx
rename to src/components/dialogs/network-modifications/two-windings-transformer/creation/two-windings-transformer-creation-dialog.tsx
index 9c9a3ec9b6..f60f7d434a 100644
--- a/src/components/dialogs/network-modifications/two-windings-transformer/creation/two-windings-transformer-creation-dialog.jsx
+++ b/src/components/dialogs/network-modifications/two-windings-transformer/creation/two-windings-transformer-creation-dialog.tsx
@@ -11,7 +11,10 @@ import {
     copyEquipmentPropertiesForCreation,
     creationPropertiesSchema,
     CustomFormProvider,
+    DeepNullable,
     emptyProperties,
+    EquipmentType,
+    EquipmentWithProperties,
     FieldType,
     getPropertiesFromModification,
     sanitizeString,
@@ -20,7 +23,7 @@ import {
     useSnackMessage,
 } from '@gridsuite/commons-ui';
 import { yupResolver } from '@hookform/resolvers/yup';
-import { Grid } from '@mui/material';
+import { Breakpoint, Grid } from '@mui/material';
 import {
     B,
     BUS_OR_BUSBAR_SECTION,
@@ -63,10 +66,8 @@ import {
     X,
 } from 'components/utils/field-constants';
 import { EQUIPMENT_TYPES } from 'components/utils/equipment-types';
-import PropTypes from 'prop-types';
 import { useCallback, useEffect, useState } from 'react';
-import { useForm } from 'react-hook-form';
-import { FetchStatus } from '../../../../../services/utils';
+import { Resolver, useForm } from 'react-hook-form';
 import EquipmentSearchDialog from '../../../equipment-search-dialog';
 import { useFormSearchCopy } from '../../../commons/use-form-search-copy';
 import {
@@ -84,11 +85,13 @@ import {
     getPhaseTapChangerEmptyFormData,
     getPhaseTapChangerFormData,
     getPhaseTapChangerValidationSchema,
+    PhaseTapChangerFormSchema,
 } from '../tap-changer-pane/phase-tap-changer-pane/phase-tap-changer-pane-utils';
 import {
     getRatioTapChangerEmptyFormData,
     getRatioTapChangerFormData,
     getRatioTapChangerValidationSchema,
+    RatioTapChangerFormSchema,
 } from '../tap-changer-pane/ratio-tap-changer-pane/ratio-tap-changer-pane-utils';
 import TwoWindingsTransformerCreationDialogTabs from './two-windings-transformer-creation-dialog-tabs';
 import TwoWindingsTransformerCreationCharacteristicsPane from './characteristics-pane/two-windings-transformer-creation-characteristics-pane';
@@ -101,6 +104,7 @@ import {
     getAllLimitsFormData,
     getLimitsEmptyFormData,
     getLimitsValidationSchema,
+    LimitsFormSchema,
     sanitizeLimitsGroups,
 } from '../../../limits/limits-pane-utils';
 import { useOpenShortWaitFetching } from 'components/dialogs/commons/handle-modification-form';
@@ -108,7 +112,24 @@ import TwoWindingsTransformerCreationDialogHeader from './two-windings-transform
 import { addSelectedFieldToRows, computeHighTapPosition, formatCompleteCurrentLimit } from 'components/utils/utils';
 import { createTwoWindingsTransformer } from '../../../../../services/study/network-modifications';
 import { TwoWindingsTransformerCreationDialogTab } from '../two-windings-transformer-utils';
-
+import { UUID } from 'node:crypto';
+import { CurrentTreeNode } from 'components/graph/tree-node.type';
+import { FetchStatus } from 'services/utils.type';
+import {
+    CharacteristicsCreationFormSchema,
+    ConnectivityFormSchema,
+    TapChangerMapInfos,
+    TwoWindingsTransformerMapInfos,
+} from '../two-windings-transformer.types';
+import {
+    OperationalLimitsGroupInfos,
+    PhaseTapChangerCreationInfos,
+    RatioTapChangerCreationInfos,
+    TapChangerCreationInfos,
+    TwoWindingsTransformerCreationInfo,
+} from 'services/network-modification-types';
+import { CurrentLimitsData } from 'services/study/network-map.type';
+import { OperationalLimitsGroupFormSchema } from 'components/dialogs/limits/operational-limits-groups-types';
 /**
  * Dialog to create a two windings transformer in the network
  * @param studyUuid the study we are currently working on
@@ -143,6 +164,25 @@ const formSchema = yup
     .concat(creationPropertiesSchema)
     .required();
 
+type BaseFormValues = yup.InferType<typeof formSchema>;
+
+export type TwoWindingsTransformerCreationFormValues = BaseFormValues & {
+    [CHARACTERISTICS]: CharacteristicsCreationFormSchema;
+    [LIMITS]: LimitsFormSchema;
+    [RATIO_TAP_CHANGER]: RatioTapChangerFormSchema;
+    [PHASE_TAP_CHANGER]: PhaseTapChangerFormSchema;
+};
+
+export interface TwoWindingsTransformerCreationDialogProps {
+    editData?: TwoWindingsTransformerCreationInfo;
+    studyUuid: UUID;
+    currentNode: CurrentTreeNode;
+    currentRootNetworkUuid: UUID;
+    isUpdate?: boolean;
+    editDataFetchStatus?: (typeof FetchStatus)[keyof typeof FetchStatus];
+    onClose: () => void;
+    onValidated?: () => void;
+}
 const TwoWindingsTransformerCreationDialog = ({
     editData,
     studyUuid,
@@ -151,22 +191,26 @@ const TwoWindingsTransformerCreationDialog = ({
     isUpdate,
     editDataFetchStatus,
     ...dialogProps
-}) => {
+}: TwoWindingsTransformerCreationDialogProps) => {
     const currentNodeUuid = currentNode?.id;
     const { snackError } = useSnackMessage();
 
-    const formMethods = useForm({
+    const formMethods = useForm<DeepNullable<TwoWindingsTransformerCreationFormValues>>({
         defaultValues: emptyFormData,
-        resolver: yupResolver(formSchema),
+        resolver: yupResolver(formSchema) as unknown as Resolver<
+            DeepNullable<TwoWindingsTransformerCreationFormValues>
+        >,
     });
 
     const { reset } = formMethods;
 
     const [tabIndex, setTabIndex] = useState(TwoWindingsTransformerCreationDialogTab.CHARACTERISTICS_TAB);
-    const [tabIndexesWithError, setTabIndexesWithError] = useState([]);
-    const [dialogWidth, setDialogWidth] = useState('xl');
+    const [tabIndexesWithError, setTabIndexesWithError] = useState<number[]>([]);
+    const [dialogWidth, setDialogWidth] = useState<Breakpoint>('xl');
 
-    const computeRatioTapChangerRegulationMode = (ratioTapChangerFormValues) => {
+    const computeRatioTapChangerRegulationMode = (
+        ratioTapChangerFormValues?: RatioTapChangerCreationInfos | TapChangerMapInfos | null
+    ) => {
         if (ratioTapChangerFormValues?.[REGULATING]) {
             return RATIO_REGULATION_MODES.VOLTAGE_REGULATION.id;
         } else {
@@ -174,40 +218,44 @@ const TwoWindingsTransformerCreationDialog = ({
         }
     };
 
-    const getTapSideForEdit = (twt, tap) => {
-        return tap?.terminalRefConnectableId === twt.equipmentId
-            ? tap?.terminalRefConnectableVlId === twt?.voltageLevelId1
-                ? SIDE.SIDE1.id
-                : SIDE.SIDE2.id
-            : null;
+    const getTapSideForEdit = (
+        twt: TwoWindingsTransformerCreationInfo,
+        tap: TapChangerCreationInfos | null | undefined
+    ) => {
+        if (tap?.terminalRefConnectableId !== twt.equipmentId) {
+            return null;
+        }
+        return tap?.terminalRefConnectableVlId === twt?.voltageLevelId1 ? SIDE.SIDE1.id : SIDE.SIDE2.id;
     };
 
-    const getTapSideForCopy = (twt, tap) => {
-        return tap?.regulatingTerminalConnectableId === twt.id
-            ? tap?.terminalRefConnectableVlId === twt?.voltageLevelId1
-                ? SIDE.SIDE1.id
-                : SIDE.SIDE2.id
-            : null;
+    const getTapSideForCopy = (twt: TwoWindingsTransformerMapInfos, tap: TapChangerMapInfos | null | undefined) => {
+        if (tap?.regulatingTerminalConnectableId !== twt.id) {
+            return null;
+        }
+        return tap?.regulatingTerminalVlId === twt?.voltageLevelId1 ? SIDE.SIDE1.id : SIDE.SIDE2.id;
     };
 
-    const getRegulationTypeForEdit = (twt, tap) => {
-        return tap?.terminalRefConnectableId != null
-            ? tap?.terminalRefConnectableId === twt.equipmentId
-                ? REGULATION_TYPES.LOCAL.id
-                : REGULATION_TYPES.DISTANT.id
-            : null;
+    const getRegulationTypeForEdit = (twt: TwoWindingsTransformerCreationInfo, tap: TapChangerCreationInfos | null) => {
+        if (tap?.terminalRefConnectableId == null) {
+            return null;
+        }
+        return tap.terminalRefConnectableId === twt.equipmentId
+            ? REGULATION_TYPES.LOCAL.id
+            : REGULATION_TYPES.DISTANT.id;
     };
 
-    const getRegulationTypeForCopy = (twt, tap) => {
-        return tap?.regulatingTerminalConnectableId != null
-            ? tap?.regulatingTerminalConnectableId === twt.id
-                ? REGULATION_TYPES.LOCAL.id
-                : REGULATION_TYPES.DISTANT.id
-            : null;
+    const getRegulationTypeForCopy = (
+        twt: TwoWindingsTransformerMapInfos,
+        tap: TapChangerMapInfos | null | undefined
+    ) => {
+        if (tap?.regulatingTerminalConnectableId == null) {
+            return null;
+        }
+        return tap.regulatingTerminalConnectableId === twt.id ? REGULATION_TYPES.LOCAL.id : REGULATION_TYPES.DISTANT.id;
     };
 
     const fromEditDataToFormValues = useCallback(
-        (twt) => {
+        (twt: TwoWindingsTransformerCreationInfo) => {
             reset({
                 [EQUIPMENT_ID]: twt.equipmentId,
                 [EQUIPMENT_NAME]: twt.equipmentName,
@@ -222,9 +270,12 @@ const TwoWindingsTransformerCreationDialog = ({
                     ...getConnectivityFormData(
                         {
                             busbarSectionId: twt.busOrBusbarSectionId1,
-                            connectionDirection: twt.connectionDirection1,
+                            connectionDirection: twt.connectionDirection1 ?? null,
                             connectionName: twt.connectionName1,
-                            connectionPosition: twt.connectionPosition1,
+                            connectionPosition:
+                                twt.connectionPosition1 !== null && twt.connectionPosition1 !== undefined
+                                    ? Number(twt.connectionPosition1)
+                                    : null,
                             voltageLevelId: twt.voltageLevelId1,
                             terminalConnected: twt.connected1,
                         },
@@ -233,9 +284,12 @@ const TwoWindingsTransformerCreationDialog = ({
                     ...getConnectivityFormData(
                         {
                             busbarSectionId: twt.busOrBusbarSectionId2,
-                            connectionDirection: twt.connectionDirection2,
+                            connectionDirection: twt.connectionDirection2 ?? null,
                             connectionName: twt.connectionName2,
-                            connectionPosition: twt.connectionPosition2,
+                            connectionPosition:
+                                twt.connectionPosition2 !== null && twt.connectionPosition2 !== undefined
+                                    ? Number(twt.connectionPosition2)
+                                    : null,
                             voltageLevelId: twt.voltageLevelId2,
                             terminalConnected: twt.connected2,
                         },
@@ -243,11 +297,26 @@ const TwoWindingsTransformerCreationDialog = ({
                     ),
                 }),
                 ...getAllLimitsFormData(
-                    twt?.operationalLimitsGroups?.map(({ id, ...baseData }) => ({
-                        ...baseData,
-                        name: id,
-                        id: id + baseData.applicability,
-                    })),
+                    twt?.operationalLimitsGroups
+                        ?.filter(
+                            (group): group is OperationalLimitsGroupInfos & { id: string; applicability: string } =>
+                                group.id != null && group.applicability != null
+                        )
+                        .map(({ id, currentLimits, applicability, limitsProperties }) => ({
+                            id: id + applicability,
+                            name: id,
+                            applicability,
+                            limitsProperties: limitsProperties ?? undefined,
+                            currentLimits: {
+                                permanentLimit: currentLimits?.permanentLimit ?? null,
+                                temporaryLimits:
+                                    currentLimits?.temporaryLimits?.map((tl) => ({
+                                        name: tl.name ?? undefined,
+                                        value: tl.value ?? undefined,
+                                        acceptableDuration: tl.acceptableDuration ?? undefined,
+                                    })) ?? [],
+                            },
+                        })),
                     twt?.selectedOperationalLimitsGroupId1 ?? null,
                     twt?.selectedOperationalLimitsGroupId2 ?? null
                 ),
@@ -268,12 +337,12 @@ const TwoWindingsTransformerCreationDialog = ({
                             : null,
                     targetDeadband: twt?.[PHASE_TAP_CHANGER]?.[TARGET_DEADBAND],
                     lowTapPosition: twt?.[PHASE_TAP_CHANGER]?.[LOW_TAP_POSITION],
-                    highTapPosition: computeHighTapPosition(twt?.[PHASE_TAP_CHANGER]?.[STEPS]),
+                    highTapPosition: computeHighTapPosition(twt?.[PHASE_TAP_CHANGER]?.[STEPS] ?? []),
                     tapPosition: twt?.[PHASE_TAP_CHANGER]?.[TAP_POSITION],
-                    steps: addSelectedFieldToRows(twt?.[PHASE_TAP_CHANGER]?.[STEPS]),
-                    equipmentId: twt?.[PHASE_TAP_CHANGER]?.terminalRefConnectableId,
-                    equipmentType: twt?.[PHASE_TAP_CHANGER]?.terminalRefConnectableType,
-                    voltageLevelId: twt?.[PHASE_TAP_CHANGER]?.terminalRefConnectableVlId,
+                    steps: addSelectedFieldToRows(twt?.[PHASE_TAP_CHANGER]?.[STEPS] ?? []),
+                    equipmentId: twt?.[PHASE_TAP_CHANGER]?.terminalRefConnectableId ?? undefined,
+                    equipmentType: twt?.[PHASE_TAP_CHANGER]?.terminalRefConnectableType ?? undefined,
+                    voltageLevelId: twt?.[PHASE_TAP_CHANGER]?.terminalRefConnectableVlId ?? undefined,
                 }),
                 ...getRatioTapChangerFormData({
                     enabled: twt?.[RATIO_TAP_CHANGER]?.[TAP_POSITION] !== undefined,
@@ -284,21 +353,21 @@ const TwoWindingsTransformerCreationDialog = ({
                     targetV: twt?.[RATIO_TAP_CHANGER]?.[TARGET_V],
                     targetDeadband: twt?.[RATIO_TAP_CHANGER]?.[TARGET_DEADBAND],
                     lowTapPosition: twt?.[RATIO_TAP_CHANGER]?.[LOW_TAP_POSITION],
-                    highTapPosition: computeHighTapPosition(twt?.[RATIO_TAP_CHANGER]?.[STEPS]),
+                    highTapPosition: computeHighTapPosition(twt?.[RATIO_TAP_CHANGER]?.[STEPS] ?? []),
                     tapPosition: twt?.[RATIO_TAP_CHANGER]?.[TAP_POSITION],
-                    steps: addSelectedFieldToRows(twt?.[RATIO_TAP_CHANGER]?.[STEPS]),
-                    equipmentId: twt?.[RATIO_TAP_CHANGER]?.terminalRefConnectableId,
-                    equipmentType: twt?.[RATIO_TAP_CHANGER]?.terminalRefConnectableType,
-                    voltageLevelId: twt?.[RATIO_TAP_CHANGER]?.terminalRefConnectableVlId,
+                    steps: addSelectedFieldToRows(twt?.[RATIO_TAP_CHANGER]?.[STEPS] ?? []),
+                    equipmentId: twt?.[RATIO_TAP_CHANGER]?.terminalRefConnectableId ?? undefined,
+                    equipmentType: twt?.[RATIO_TAP_CHANGER]?.terminalRefConnectableType ?? undefined,
+                    voltageLevelId: twt?.[RATIO_TAP_CHANGER]?.terminalRefConnectableVlId ?? undefined,
                 }),
                 ...getPropertiesFromModification(twt.properties),
-            });
+            } as DeepNullable<TwoWindingsTransformerCreationFormValues>);
         },
         [reset]
     );
 
     const fromSearchCopyToFormValues = useCallback(
-        (twt) => {
+        (twt: TwoWindingsTransformerMapInfos) => {
             reset(
                 {
                     [EQUIPMENT_ID]: twt.id + '(1)',
@@ -310,11 +379,11 @@ const TwoWindingsTransformerCreationDialog = ({
                         b: convertInputValue(FieldType.B, twt.b),
                         ratedU1: twt.ratedU1,
                         ratedU2: twt.ratedU2,
-                        ratedS: twt.ratedS,
+                        ratedS: twt.ratedS ?? null,
                         ...getConnectivityFormData(
                             {
                                 busbarSectionId: twt.busOrBusbarSectionId1,
-                                connectionDirection: twt.connectablePosition1?.connectionDirection,
+                                connectionDirection: twt.connectablePosition1?.connectionDirection ?? null,
                                 connectionName: twt.connectablePosition1?.connectionName,
                                 voltageLevelId: twt.voltageLevelId1,
                             },
@@ -323,7 +392,7 @@ const TwoWindingsTransformerCreationDialog = ({
                         ...getConnectivityFormData(
                             {
                                 busbarSectionId: twt.busOrBusbarSectionId2,
-                                connectionDirection: twt.connectablePosition2?.connectionDirection,
+                                connectionDirection: twt.connectablePosition2?.connectionDirection ?? null,
                                 connectionName: twt.connectablePosition2?.connectionName,
                                 voltageLevelId: twt.voltageLevelId2,
                             },
@@ -331,7 +400,7 @@ const TwoWindingsTransformerCreationDialog = ({
                         ),
                     }),
                     ...getAllLimitsFormData(
-                        formatCompleteCurrentLimit(twt.currentLimits),
+                        formatCompleteCurrentLimit(twt.currentLimits as CurrentLimitsData[]),
                         twt.selectedOperationalLimitsGroupId1 ?? null,
                         twt.selectedOperationalLimitsGroupId2 ?? null
                     ),
@@ -342,16 +411,16 @@ const TwoWindingsTransformerCreationDialog = ({
                         regulationType: getRegulationTypeForCopy(twt, twt?.[RATIO_TAP_CHANGER]),
                         regulationSide: getTapSideForCopy(twt, twt?.[RATIO_TAP_CHANGER]),
                         targetV: twt?.[RATIO_TAP_CHANGER]?.[TARGET_V],
-                        targetDeadband: isNaN(twt?.[RATIO_TAP_CHANGER]?.[TARGET_DEADBAND])
+                        targetDeadband: Number.isNaN(twt?.[RATIO_TAP_CHANGER]?.[TARGET_DEADBAND] ?? Number.NaN)
                             ? null
                             : twt?.[RATIO_TAP_CHANGER]?.[TARGET_DEADBAND],
                         lowTapPosition: twt?.[RATIO_TAP_CHANGER]?.[LOW_TAP_POSITION],
-                        highTapPosition: computeHighTapPosition(twt?.[RATIO_TAP_CHANGER]?.[STEPS]),
+                        highTapPosition: computeHighTapPosition(twt?.[RATIO_TAP_CHANGER]?.[STEPS] ?? []),
                         tapPosition: twt?.[RATIO_TAP_CHANGER]?.[TAP_POSITION],
-                        steps: addSelectedFieldToRows(twt?.[RATIO_TAP_CHANGER]?.[STEPS]),
+                        steps: addSelectedFieldToRows(twt?.[RATIO_TAP_CHANGER]?.[STEPS] ?? []),
                         equipmentId: twt?.[RATIO_TAP_CHANGER]?.regulatingTerminalConnectableId,
                         equipmentType: twt?.[RATIO_TAP_CHANGER]?.regulatingTerminalConnectableType,
-                        voltageLevelId: twt?.[RATIO_TAP_CHANGER]?.terminalRefConnectableVlId,
+                        voltageLevelId: twt?.[RATIO_TAP_CHANGER]?.regulatingTerminalVlId,
                     }),
                     ...getPhaseTapChangerFormData({
                         enabled: twt?.[PHASE_TAP_CHANGER]?.[TAP_POSITION] !== undefined,
@@ -369,19 +438,19 @@ const TwoWindingsTransformerCreationDialog = ({
                             PHASE_REGULATION_MODES.ACTIVE_POWER_CONTROL.id
                                 ? twt?.[PHASE_TAP_CHANGER]?.regulationValue
                                 : null,
-                        targetDeadband: isNaN(twt?.[PHASE_TAP_CHANGER]?.[TARGET_DEADBAND])
+                        targetDeadband: Number.isNaN(twt?.[PHASE_TAP_CHANGER]?.[TARGET_DEADBAND] ?? Number.NaN)
                             ? null
                             : twt?.[PHASE_TAP_CHANGER]?.[TARGET_DEADBAND],
                         lowTapPosition: twt?.[PHASE_TAP_CHANGER]?.[LOW_TAP_POSITION],
-                        highTapPosition: computeHighTapPosition(twt?.[PHASE_TAP_CHANGER]?.[STEPS]),
+                        highTapPosition: computeHighTapPosition(twt?.[PHASE_TAP_CHANGER]?.[STEPS] ?? []),
                         tapPosition: twt?.[PHASE_TAP_CHANGER]?.[TAP_POSITION],
-                        steps: addSelectedFieldToRows(twt?.[PHASE_TAP_CHANGER]?.[STEPS]),
-                        voltageLevelId: twt?.[PHASE_TAP_CHANGER]?.terminalRefConnectableVlId,
+                        steps: addSelectedFieldToRows(twt?.[PHASE_TAP_CHANGER]?.[STEPS] ?? []),
+                        voltageLevelId: twt?.[PHASE_TAP_CHANGER]?.regulatingTerminalVlId,
                         equipmentId: twt?.[PHASE_TAP_CHANGER]?.regulatingTerminalConnectableId,
                         equipmentType: twt?.[PHASE_TAP_CHANGER]?.regulatingTerminalConnectableType,
                     }),
-                    ...copyEquipmentPropertiesForCreation(twt),
-                },
+                    ...copyEquipmentPropertiesForCreation(twt as EquipmentWithProperties),
+                } as DeepNullable<TwoWindingsTransformerCreationFormValues>,
                 { keepDefaultValues: true }
             );
         },
@@ -408,18 +477,18 @@ const TwoWindingsTransformerCreationDialog = ({
         </Grid>
     );
 
-    const computeRatioTapChangerRegulating = (ratioTapChangerFormValues) => {
+    const computeRatioTapChangerRegulating = (ratioTapChangerFormValues: RatioTapChangerFormSchema) => {
         return ratioTapChangerFormValues?.[REGULATION_MODE] === RATIO_REGULATION_MODES.VOLTAGE_REGULATION.id;
     };
 
-    const computePhaseTapChangerRegulating = (phaseTapChangerFormValues) => {
+    const computePhaseTapChangerRegulating = (phaseTapChangerFormValues: PhaseTapChangerFormSchema) => {
         return (
             phaseTapChangerFormValues?.[REGULATION_MODE] === PHASE_REGULATION_MODES.CURRENT_LIMITER.id ||
             phaseTapChangerFormValues?.[REGULATION_MODE] === PHASE_REGULATION_MODES.ACTIVE_POWER_CONTROL.id
         );
     };
 
-    const computeRegulationModeValue = (phaseTapChangerFormValues) => {
+    const computeRegulationModeValue = (phaseTapChangerFormValues: PhaseTapChangerFormSchema) => {
         if (phaseTapChangerFormValues?.[REGULATION_MODE] === PHASE_REGULATION_MODES.OFF.id) {
             return null;
         }
@@ -427,18 +496,18 @@ const TwoWindingsTransformerCreationDialog = ({
         return phaseTapChangerFormValues?.[REGULATION_MODE];
     };
 
-    const computePhaseTapChangerRegulationValue = (phaseTapChangerFormValues) => {
+    const computePhaseTapChangerRegulationValue = (phaseTapChangerFormValues: PhaseTapChangerFormSchema) => {
         switch (phaseTapChangerFormValues?.[REGULATION_MODE]) {
             case PHASE_REGULATION_MODES.ACTIVE_POWER_CONTROL.id:
-                return phaseTapChangerFormValues?.[FLOW_SET_POINT_REGULATING_VALUE];
+                return phaseTapChangerFormValues?.[FLOW_SET_POINT_REGULATING_VALUE] ?? undefined;
             case PHASE_REGULATION_MODES.CURRENT_LIMITER.id:
-                return phaseTapChangerFormValues?.[CURRENT_LIMITER_REGULATING_VALUE];
+                return phaseTapChangerFormValues?.[CURRENT_LIMITER_REGULATING_VALUE] ?? undefined;
             default:
                 return undefined;
         }
     };
 
-    const computeRegulatingTerminalType = (tapChangerValue) => {
+    const computeRegulatingTerminalType = (tapChangerValue: RatioTapChangerFormSchema | PhaseTapChangerFormSchema) => {
         if (tapChangerValue?.[EQUIPMENT]?.type) {
             return tapChangerValue?.[EQUIPMENT]?.type;
         }
@@ -450,7 +519,11 @@ const TwoWindingsTransformerCreationDialog = ({
         return undefined;
     };
 
-    const computeTapTerminalVlId = (tapChangerValue, connectivity1, connectivity2) => {
+    const computeTapTerminalVlId = (
+        tapChangerValue: RatioTapChangerFormSchema | PhaseTapChangerFormSchema,
+        connectivity1: ConnectivityFormSchema,
+        connectivity2: ConnectivityFormSchema
+    ) => {
         if (tapChangerValue?.[REGULATION_TYPE] === REGULATION_TYPES.LOCAL.id) {
             if (tapChangerValue?.[REGULATION_SIDE] === SIDE.SIDE1.id) {
                 return connectivity1?.[VOLTAGE_LEVEL]?.[ID];
@@ -462,7 +535,10 @@ const TwoWindingsTransformerCreationDialog = ({
         }
     };
 
-    const computeRegulatingTerminalId = (tapChangerValue, currentTwtId) => {
+    const computeRegulatingTerminalId = (
+        tapChangerValue: RatioTapChangerFormSchema | PhaseTapChangerFormSchema,
+        currentTwtId: string
+    ) => {
         if (tapChangerValue?.[REGULATION_TYPE] === REGULATION_TYPES.LOCAL.id) {
             return currentTwtId;
         } else {
@@ -471,7 +547,7 @@ const TwoWindingsTransformerCreationDialog = ({
     };
 
     const onSubmit = useCallback(
-        (twt) => {
+        (twt: TwoWindingsTransformerCreationFormValues) => {
             const enablePhaseTapChanger = twt[PHASE_TAP_CHANGER]?.[ENABLED];
             const enableRatioTapChanger = twt[RATIO_TAP_CHANGER]?.[ENABLED];
             const characteristics = twt[CHARACTERISTICS];
@@ -485,35 +561,28 @@ const TwoWindingsTransformerCreationDialog = ({
                 const ratioTapChangerFormValues = twt[RATIO_TAP_CHANGER];
                 const hasLoadTapCapabilities = ratioTapChangerFormValues[LOAD_TAP_CHANGING_CAPABILITIES];
 
-                const getRegulatingValue = (computeFunc, ...args) => {
-                    return hasLoadTapCapabilities ? computeFunc(...args) : null;
-                };
-
-                const getValueOrDefault = (key) => {
+                const getValueOrDefault = (key: keyof RatioTapChangerFormSchema) => {
                     return hasLoadTapCapabilities ? ratioTapChangerFormValues[key] : null;
                 };
 
                 ratioTap = {
                     ...ratioTapChangerFormValues,
                     isRegulating: computeRatioTapChangerRegulating(ratioTapChangerFormValues),
-                    terminalRefConnectableId: getRegulatingValue(
-                        computeRegulatingTerminalId,
-                        ratioTapChangerFormValues,
-                        twt[EQUIPMENT_ID]
-                    ),
-                    terminalRefConnectableType: getRegulatingValue(
-                        computeRegulatingTerminalType,
-                        ratioTapChangerFormValues
-                    ),
-                    terminalRefConnectableVlId: getRegulatingValue(
-                        computeTapTerminalVlId,
-                        ratioTapChangerFormValues,
-                        characteristics[CONNECTIVITY_1],
-                        characteristics[CONNECTIVITY_2]
-                    ),
+                    terminalRefConnectableId: hasLoadTapCapabilities
+                        ? computeRegulatingTerminalId(ratioTapChangerFormValues, twt[EQUIPMENT_ID])
+                        : null,
+                    terminalRefConnectableType: hasLoadTapCapabilities
+                        ? computeRegulatingTerminalType(ratioTapChangerFormValues)
+                        : null,
+                    terminalRefConnectableVlId: hasLoadTapCapabilities
+                        ? computeTapTerminalVlId(
+                              ratioTapChangerFormValues,
+                              characteristics[CONNECTIVITY_1],
+                              characteristics[CONNECTIVITY_2]
+                          )
+                        : null,
                     targetV: getValueOrDefault(TARGET_V),
                     targetDeadband: getValueOrDefault(TARGET_DEADBAND),
-                    regulationType: getValueOrDefault(REGULATION_TYPE),
                 };
             }
             let phaseTap = undefined;
@@ -538,37 +607,39 @@ const TwoWindingsTransformerCreationDialog = ({
             createTwoWindingsTransformer({
                 studyUuid: studyUuid,
                 nodeUuid: currentNodeUuid,
-                twoWindingsTransformerId: twt[EQUIPMENT_ID],
-                twoWindingsTransformerName: sanitizeString(twt[EQUIPMENT_NAME]),
+                equipmentId: twt[EQUIPMENT_ID],
+                equipmentName: sanitizeString(twt[EQUIPMENT_NAME]),
                 r: characteristics[R],
-                x: characteristics[X],
-                g: characteristics[G],
-                b: characteristics[B],
-                ratedS: characteristics[RATED_S] ?? '',
-                ratedU1: characteristics[RATED_U1],
-                ratedU2: characteristics[RATED_U2],
-                limitsGroups: sanitizeLimitsGroups(limits[OPERATIONAL_LIMITS_GROUPS]),
-                selectedLimitsGroup1: limits[SELECTED_OPERATIONAL_LIMITS_GROUP_ID1],
-                selectedLimitsGroup2: limits[SELECTED_OPERATIONAL_LIMITS_GROUP_ID2],
-                voltageLevelId1: characteristics[CONNECTIVITY_1]?.[VOLTAGE_LEVEL]?.[ID],
-                busOrBusbarSectionId1: characteristics[CONNECTIVITY_1]?.[BUS_OR_BUSBAR_SECTION]?.[ID],
-                voltageLevelId2: characteristics[CONNECTIVITY_2]?.[VOLTAGE_LEVEL]?.[ID],
-                busOrBusbarSectionId2: characteristics[CONNECTIVITY_2]?.[BUS_OR_BUSBAR_SECTION]?.[ID],
-                ratioTapChanger: ratioTap,
-                phaseTapChanger: phaseTap,
+                x: Number(characteristics[X]),
+                g: Number(characteristics[G]),
+                b: Number(characteristics[B]),
+                ratedS: characteristics[RATED_S],
+                ratedU1: Number(characteristics[RATED_U1]),
+                ratedU2: Number(characteristics[RATED_U2]),
+                operationalLimitsGroups: sanitizeLimitsGroups(
+                    limits[OPERATIONAL_LIMITS_GROUPS] as OperationalLimitsGroupFormSchema[]
+                ) as OperationalLimitsGroupInfos[],
+                selectedOperationalLimitsGroupId1: String(limits[SELECTED_OPERATIONAL_LIMITS_GROUP_ID1]),
+                selectedOperationalLimitsGroupId2: String(limits[SELECTED_OPERATIONAL_LIMITS_GROUP_ID2]),
+                voltageLevelId1: String(characteristics[CONNECTIVITY_1]?.[VOLTAGE_LEVEL]?.[ID]),
+                busOrBusbarSectionId1: String(characteristics[CONNECTIVITY_1]?.[BUS_OR_BUSBAR_SECTION]?.[ID]),
+                voltageLevelId2: String(characteristics[CONNECTIVITY_2]?.[VOLTAGE_LEVEL]?.[ID]),
+                busOrBusbarSectionId2: String(characteristics[CONNECTIVITY_2]?.[BUS_OR_BUSBAR_SECTION]?.[ID]),
+                ratioTapChanger: (ratioTap as RatioTapChangerCreationInfos) ?? null,
+                phaseTapChanger: (phaseTap as PhaseTapChangerCreationInfos) ?? null,
                 isUpdate: !!editData,
-                modificationUuid: editData ? editData.uuid : undefined,
+                uuid: editData ? editData.uuid : '',
                 connectionName1: sanitizeString(characteristics[CONNECTIVITY_1]?.[CONNECTION_NAME]),
                 connectionDirection1:
                     characteristics[CONNECTIVITY_1]?.[CONNECTION_DIRECTION] ?? UNDEFINED_CONNECTION_DIRECTION,
                 connectionName2: sanitizeString(characteristics[CONNECTIVITY_2]?.[CONNECTION_NAME]),
                 connectionDirection2:
                     characteristics[CONNECTIVITY_2]?.[CONNECTION_DIRECTION] ?? UNDEFINED_CONNECTION_DIRECTION,
-                connectionPosition1: characteristics[CONNECTIVITY_1]?.[CONNECTION_POSITION] ?? null,
-                connectionPosition2: characteristics[CONNECTIVITY_2]?.[CONNECTION_POSITION] ?? null,
-                connected1: characteristics[CONNECTIVITY_1]?.[CONNECTED] ?? null,
-                connected2: characteristics[CONNECTIVITY_2]?.[CONNECTED] ?? null,
-                properties: toModificationProperties(twt),
+                connectionPosition1: String(characteristics[CONNECTIVITY_1]?.[CONNECTION_POSITION]),
+                connectionPosition2: String(characteristics[CONNECTIVITY_2]?.[CONNECTION_POSITION]),
+                connected1: Boolean(characteristics[CONNECTIVITY_1]?.[CONNECTED]),
+                connected2: Boolean(characteristics[CONNECTIVITY_2]?.[CONNECTED]),
+                properties: toModificationProperties(twt as unknown as Record<string, unknown>),
             }).catch((error) => {
                 snackWithFallback(snackError, error, { headerId: 'TwoWindingsTransformerCreationError' });
             });
@@ -577,7 +648,7 @@ const TwoWindingsTransformerCreationDialog = ({
     );
 
     const onValidationError = useCallback(
-        (errors) => {
+        (errors: Record<string, unknown>) => {
             const tabsInError = [];
             if (errors?.[PHASE_TAP_CHANGER] !== undefined) {
                 tabsInError.push(TwoWindingsTransformerCreationDialogTab.PHASE_TAP_TAB);
@@ -615,7 +686,7 @@ const TwoWindingsTransformerCreationDialog = ({
     });
 
     return (
-        <CustomFormProvider validationSchema={formSchema} {...formMethods}>
+        <CustomFormProvider validationSchema={formSchema as any} {...formMethods}>
             <ModificationDialog
                 fullWidth
                 onClear={clear}
@@ -644,7 +715,7 @@ const TwoWindingsTransformerCreationDialog = ({
                 <EquipmentSearchDialog
                     open={searchCopy.isDialogSearchOpen}
                     onClose={searchCopy.handleCloseSearchDialog}
-                    equipmentType={EQUIPMENT_TYPES.TWO_WINDINGS_TRANSFORMER}
+                    equipmentType={EquipmentType.TWO_WINDINGS_TRANSFORMER}
                     onSelectionChange={searchCopy.handleSelectionChange}
                     currentNodeUuid={currentNodeUuid}
                     currentRootNetworkUuid={currentRootNetworkUuid}
@@ -654,13 +725,4 @@ const TwoWindingsTransformerCreationDialog = ({
     );
 };
 
-TwoWindingsTransformerCreationDialog.propTypes = {
-    editData: PropTypes.object,
-    studyUuid: PropTypes.string,
-    currentNode: PropTypes.object,
-    currentRootNetworkUuid: PropTypes.string,
-    isUpdate: PropTypes.bool,
-    editDataFetchStatus: PropTypes.string,
-};
-
 export default TwoWindingsTransformerCreationDialog;
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog-header.jsx b/src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog-header.tsx
similarity index 84%
rename from src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog-header.jsx
rename to src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog-header.tsx
index 2405cfc79f..439fbf6f76 100644
--- a/src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog-header.jsx
+++ b/src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog-header.tsx
@@ -10,7 +10,15 @@ import { ENABLED, EQUIPMENT_NAME, RATIO_TAP_CHANGER, PHASE_TAP_CHANGER } from 'c
 import { filledTextField, SwitchInput, TextInput } from '@gridsuite/commons-ui';
 import GridItem from '../../../commons/grid-item';
 
-const TwoWindingsTransformerModificationDialogHeader = ({ equipmentToModify, equipmentId }) => {
+interface TwoWindingsTransformerModificationDialogHeaderProps {
+    equipmentToModify?: string;
+    equipmentId: string | null;
+}
+
+const TwoWindingsTransformerModificationDialogHeader = ({
+    equipmentToModify,
+    equipmentId,
+}: TwoWindingsTransformerModificationDialogHeaderProps) => {
     const twoWindingsTransformerIdField = (
         <TextField
             size="small"
@@ -30,7 +38,7 @@ const TwoWindingsTransformerModificationDialogHeader = ({ equipmentToModify, equ
             name={EQUIPMENT_NAME}
             label="Name"
             formProps={filledTextField}
-            previousValue={equipmentToModify?.name}
+            previousValue={equipmentToModify}
             clearable
         />
     );
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog-tabs.jsx b/src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog-tabs.tsx
similarity index 90%
rename from src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog-tabs.jsx
rename to src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog-tabs.tsx
index 14657e3f21..38995fa559 100644
--- a/src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog-tabs.jsx
+++ b/src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog-tabs.tsx
@@ -12,7 +12,17 @@ import { ENABLED, PHASE_TAP_CHANGER, RATIO_TAP_CHANGER } from 'components/utils/
 import { getTabIndicatorStyle, getTabStyle } from '../../../../utils/tab-utils';
 import { TwoWindingsTransformerModificationDialogTab } from '../two-windings-transformer-utils';
 
-const TwoWindingsTransformerModificationDialogTabs = ({ tabIndex, tabIndexesWithError, setTabIndex }) => {
+interface TwoWindingsTransformerModificationDialogTabsProps {
+    tabIndex: number;
+    tabIndexesWithError: number[];
+    setTabIndex: (index: number) => void;
+}
+
+const TwoWindingsTransformerModificationDialogTabs = ({
+    tabIndex,
+    tabIndexesWithError,
+    setTabIndex,
+}: TwoWindingsTransformerModificationDialogTabsProps) => {
     const phaseTapChangerEnabledWatch = useWatch({
         name: `${PHASE_TAP_CHANGER}.${ENABLED}`,
     });
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog.jsx b/src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog.tsx
similarity index 69%
rename from src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog.jsx
rename to src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog.tsx
index 295c05d343..57082331b0 100644
--- a/src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog.jsx
+++ b/src/components/dialogs/network-modifications/two-windings-transformer/modification/two-windings-transformer-modification-dialog.tsx
@@ -11,6 +11,7 @@ import {
     CustomFormProvider,
     emptyProperties,
     EquipmentType,
+    EquipmentWithProperties,
     FieldConstants,
     FieldType,
     getConcatenatedProperties,
@@ -76,8 +77,8 @@ import {
     VOLTAGE_LEVEL,
     X,
 } from 'components/utils/field-constants';
-import PropTypes from 'prop-types';
 import { useCallback, useEffect, useState } from 'react';
+import { FieldErrors, Resolver } from 'react-hook-form';
 import {
     FORM_LOADING_DELAY,
     PHASE_REGULATION_MODES,
@@ -102,6 +103,7 @@ import {
     getLimitsEmptyFormData,
     getLimitsValidationSchema,
     getOpLimitsGroupInfosFromBranchModification,
+    LimitsFormSchema,
 } from '../../../limits/limits-pane-utils';
 import { useOpenShortWaitFetching } from 'components/dialogs/commons/handle-modification-form';
 import TwoWindingsTransformerModificationDialogHeader from './two-windings-transformer-modification-dialog-header';
@@ -119,6 +121,7 @@ import {
     getPhaseTapChangerEmptyFormData,
     getPhaseTapChangerFormData,
     getPhaseTapChangerValidationSchema,
+    PhaseTapChangerFormSchema,
 } from '../tap-changer-pane/phase-tap-changer-pane/phase-tap-changer-pane-utils';
 import { modifyTwoWindingsTransformer } from '../../../../../services/study/network-modifications';
 import {
@@ -126,6 +129,7 @@ import {
     getRatioTapChangerEmptyFormData,
     getRatioTapChangerFormData,
     getRatioTapChangerValidationSchema,
+    RatioTapChangerFormSchema,
 } from '../tap-changer-pane/ratio-tap-changer-pane/ratio-tap-changer-pane-utils';
 import { isNodeBuilt } from 'components/graph/util/model-functions';
 import RatioTapChangerPane from '../tap-changer-pane/ratio-tap-changer-pane/ratio-tap-changer-pane';
@@ -140,9 +144,9 @@ import {
     getConnectivityFormData,
     getCont1Cont2WithPositionEmptyFormData,
 } from '../../../connectivity/connectivity-form-utils';
-import BranchActiveReactivePowerMeasurementsForm from '../../common/measurements/branch-active-reactive-power-form.tsx';
+import BranchActiveReactivePowerMeasurementsForm from '../../common/measurements/branch-active-reactive-power-form';
 import { TwoWindingsTransformerModificationDialogTab } from '../two-windings-transformer-utils';
-import { ToBeEstimatedForm } from './2wt-to-be-estimated/to-be-estimated-form.tsx';
+import { ToBeEstimatedForm } from './2wt-to-be-estimated/to-be-estimated-form';
 import {
     getStateEstimationEditData,
     getStateEstimationEmptyFormData,
@@ -151,6 +155,37 @@ import {
 import { LimitsPane } from '../../../limits/limits-pane';
 import { useIntl } from 'react-intl';
 import { useFormWithDirtyTracking } from 'components/dialogs/commons/use-form-with-dirty-tracking';
+import { UUID } from 'node:crypto';
+import { CurrentTreeNode } from 'components/graph/tree-node.type';
+import {
+    TapChangerStep,
+    ConnectivityFormSchema,
+    CharacteristicsFormSchema,
+    StateEstimationFormSchema,
+    TwoWindingsTransformerMapInfos,
+} from '../two-windings-transformer.types';
+import { BranchInfos, CurrentLimitsData } from 'services/study/network-map.type';
+import { ToBeEstimatedInfo } from './2wt-to-be-estimated/to-be-estimated.type';
+import {
+    OperationalLimitsGroupModificationInfos,
+    PhaseTapChangerModificationInfos,
+    RatioTapChangerModificationInfos,
+    TwoWindingsTransformerModificationInfo,
+} from 'services/network-modification-types';
+import { OperationalLimitsGroupFormSchema } from 'components/dialogs/limits/operational-limits-groups-types';
+import { LineModificationFormSchema } from '../../line/modification/line-modification-type';
+
+export interface TwoWindingsTransformerModificationDialogProps {
+    studyUuid: UUID;
+    defaultIdValue?: string | null;
+    currentNode: CurrentTreeNode;
+    currentRootNetworkUuid: UUID;
+    isUpdate?: boolean;
+    editData?: TwoWindingsTransformerModificationInfo;
+    editDataFetchStatus?: (typeof FetchStatus)[keyof typeof FetchStatus];
+    onClose?: () => void;
+    onValidated?: () => void;
+}
 
 const emptyFormData = {
     [EQUIPMENT_NAME]: '',
@@ -177,6 +212,19 @@ const formSchema = yup
     .concat(modificationPropertiesSchema)
     .required();
 
+type BaseFormValues = yup.InferType<typeof formSchema>;
+
+export type TwoWindingsTransformerModificationFormValues = BaseFormValues & {
+    [CONNECTIVITY]: {
+        [CONNECTIVITY_1]: ConnectivityFormSchema;
+        [CONNECTIVITY_2]: ConnectivityFormSchema;
+    };
+    [CHARACTERISTICS]: CharacteristicsFormSchema;
+    [LIMITS]: LimitsFormSchema;
+    [RATIO_TAP_CHANGER]: RatioTapChangerFormSchema;
+    [PHASE_TAP_CHANGER]: PhaseTapChangerFormSchema;
+    [STATE_ESTIMATION]: StateEstimationFormSchema;
+};
 /**
  * Dialog to modify a two windings transformer in the network
  * @param studyUuid the study we are currently working on
@@ -190,31 +238,35 @@ const formSchema = yup
  */
 const TwoWindingsTransformerModificationDialog = ({
     studyUuid,
-    defaultIdValue, // Used to pre-select an equipmentId when calling this dialog from the SLD
+    defaultIdValue,
     currentNode,
     currentRootNetworkUuid,
     isUpdate,
-    editData, // contains data when we try to edit an existing hypothesis from the current node's list
+    editData,
     editDataFetchStatus,
     ...dialogProps
-}) => {
+}: TwoWindingsTransformerModificationDialogProps) => {
     const currentNodeUuid = currentNode?.id;
     const { snackError } = useSnackMessage();
-    const [selectedId, setSelectedId] = useState(defaultIdValue ?? null);
-    const [tabIndex, setTabIndex] = useState(TwoWindingsTransformerModificationDialogTab.CONNECTIVITY_TAB);
-    const [tabIndexesWithError, setTabIndexesWithError] = useState([]);
-    const [dataFetchStatus, setDataFetchStatus] = useState(FetchStatus.IDLE);
-    const [twtToModify, setTwtToModify] = useState(null);
+    const [selectedId, setSelectedId] = useState<string | null>(defaultIdValue ?? null);
+    const [tabIndex, setTabIndex] = useState<number>(TwoWindingsTransformerModificationDialogTab.CONNECTIVITY_TAB);
+    const [tabIndexesWithError, setTabIndexesWithError] = useState<number[]>([]);
+    const [dataFetchStatus, setDataFetchStatus] = useState<(typeof FetchStatus)[keyof typeof FetchStatus]>(
+        FetchStatus.IDLE
+    );
+    const [twtToModify, setTwtToModify] = useState<TwoWindingsTransformerMapInfos | null>(null);
     const intl = useIntl();
 
-    const formMethods = useFormWithDirtyTracking({
+    const formMethods = useFormWithDirtyTracking<TwoWindingsTransformerModificationFormValues>({
         defaultValues: emptyFormData,
-        resolver: yupResolver(formSchema),
+        resolver: yupResolver(formSchema) as unknown as Resolver<TwoWindingsTransformerModificationFormValues>,
     });
     const { reset, getValues } = formMethods;
     const voltageLevelOptions = useVoltageLevelsListInfos(studyUuid, currentNodeUuid, currentRootNetworkUuid);
 
-    const computeRatioTapChangerRegulationMode = (ratioTapChangerFormValues) => {
+    const computeRatioTapChangerRegulationMode = (
+        ratioTapChangerFormValues: RatioTapChangerModificationInfos | null
+    ): string | null => {
         if (ratioTapChangerFormValues?.[REGULATING]?.value == null) {
             return null;
         }
@@ -226,10 +278,12 @@ const TwoWindingsTransformerModificationDialog = ({
     };
 
     const fromEditDataToFormValues = useCallback(
-        (twtModification) => {
+        (twtModification: TwoWindingsTransformerModificationInfo) => {
             if (twtModification?.equipmentId) {
                 setSelectedId(twtModification.equipmentId);
             }
+            console.log('TWT Edit data:', twtModification);
+            console.log('TWT Connectivity 1:', createConnectivityData(twtModification, 1));
             reset({
                 [EQUIPMENT_NAME]: twtModification.equipmentName?.value,
                 [CONNECTIVITY]: {
@@ -237,13 +291,13 @@ const TwoWindingsTransformerModificationDialog = ({
                     ...getConnectivityFormData(createConnectivityData(twtModification, 2), CONNECTIVITY_2),
                 },
                 ...getCharacteristicsFormData({
-                    r: twtModification.r?.value,
-                    x: twtModification.x?.value,
+                    r: twtModification.r?.value ?? null,
+                    x: twtModification.x?.value ?? null,
                     g: convertInputValue(FieldType.G, twtModification.g?.value),
                     b: convertInputValue(FieldType.B, twtModification.b?.value),
-                    ratedU1: twtModification.ratedU1?.value,
-                    ratedU2: twtModification.ratedU2?.value,
-                    ratedS: twtModification.ratedS?.value,
+                    ratedU1: twtModification.ratedU1?.value ?? null,
+                    ratedU2: twtModification.ratedU2?.value ?? null,
+                    ratedS: twtModification.ratedS?.value ?? null,
                 }),
                 ...getStateEstimationEditData(STATE_ESTIMATION, twtModification),
                 ...getAllLimitsFormData(
@@ -262,9 +316,9 @@ const TwoWindingsTransformerModificationDialog = ({
                     targetV: twtModification?.[RATIO_TAP_CHANGER]?.[TARGET_V]?.value,
                     targetDeadband: twtModification?.[RATIO_TAP_CHANGER]?.[TARGET_DEADBAND]?.value,
                     lowTapPosition: twtModification?.[RATIO_TAP_CHANGER]?.[LOW_TAP_POSITION]?.value,
-                    highTapPosition: computeHighTapPosition(twtModification?.[RATIO_TAP_CHANGER]?.[STEPS]),
+                    highTapPosition: computeHighTapPosition(twtModification?.[RATIO_TAP_CHANGER]?.[STEPS] ?? []),
                     tapPosition: twtModification?.[RATIO_TAP_CHANGER]?.[TAP_POSITION]?.value,
-                    steps: addSelectedFieldToRows(twtModification?.[RATIO_TAP_CHANGER]?.[STEPS]),
+                    steps: addSelectedFieldToRows(twtModification?.[RATIO_TAP_CHANGER]?.[STEPS] ?? []),
                     equipmentId: twtModification?.[RATIO_TAP_CHANGER]?.terminalRefConnectableId?.value,
                     equipmentType: twtModification?.[RATIO_TAP_CHANGER]?.terminalRefConnectableType?.value,
                     voltageLevelId: twtModification?.[RATIO_TAP_CHANGER]?.terminalRefConnectableVlId?.value,
@@ -288,9 +342,9 @@ const TwoWindingsTransformerModificationDialog = ({
                             : undefined,
                     targetDeadband: twtModification?.[PHASE_TAP_CHANGER]?.[TARGET_DEADBAND]?.value,
                     lowTapPosition: twtModification?.[PHASE_TAP_CHANGER]?.[LOW_TAP_POSITION]?.value,
-                    highTapPosition: computeHighTapPosition(twtModification?.[PHASE_TAP_CHANGER]?.[STEPS]),
+                    highTapPosition: computeHighTapPosition(twtModification?.[PHASE_TAP_CHANGER]?.[STEPS] ?? []),
                     tapPosition: twtModification?.[PHASE_TAP_CHANGER]?.[TAP_POSITION]?.value,
-                    steps: addSelectedFieldToRows(twtModification?.[PHASE_TAP_CHANGER]?.[STEPS]),
+                    steps: addSelectedFieldToRows(twtModification?.[PHASE_TAP_CHANGER]?.[STEPS] ?? []),
                     equipmentId: twtModification?.[PHASE_TAP_CHANGER]?.terminalRefConnectableId?.value,
                     equipmentType: twtModification?.[PHASE_TAP_CHANGER]?.terminalRefConnectableType?.value,
                     voltageLevelId: twtModification?.[PHASE_TAP_CHANGER]?.terminalRefConnectableVlId?.value,
@@ -307,84 +361,107 @@ const TwoWindingsTransformerModificationDialog = ({
         }
     }, [fromEditDataToFormValues, editData]);
 
-    const computeRatioTapChangerRegulating = (ratioTapChangerFormValues) => {
+    const computeRatioTapChangerRegulating = (ratioTapChangerFormValues: RatioTapChangerFormSchema): boolean => {
         return ratioTapChangerFormValues?.[REGULATION_MODE] === RATIO_REGULATION_MODES.VOLTAGE_REGULATION.id;
     };
 
-    const computePhaseTapChangerRegulationValue = (phaseTapChangerFormValues, currentRegulationMode) => {
+    const computePhaseTapChangerRegulationValue = (
+        phaseTapChangerFormValues: PhaseTapChangerFormSchema,
+        currentRegulationMode?: string
+    ): number | undefined => {
         const regulationMode = phaseTapChangerFormValues?.[REGULATION_MODE] || currentRegulationMode;
 
         switch (regulationMode) {
             case PHASE_REGULATION_MODES.ACTIVE_POWER_CONTROL.id:
-                return phaseTapChangerFormValues?.[FLOW_SET_POINT_REGULATING_VALUE];
+                return phaseTapChangerFormValues?.[FLOW_SET_POINT_REGULATING_VALUE] ?? undefined;
             case PHASE_REGULATION_MODES.CURRENT_LIMITER.id:
-                return phaseTapChangerFormValues?.[CURRENT_LIMITER_REGULATING_VALUE];
+                return phaseTapChangerFormValues?.[CURRENT_LIMITER_REGULATING_VALUE] ?? undefined;
             default:
                 return undefined;
         }
     };
 
-    const fillPhaseTapChangerRegulationAttributes = useCallback((phaseTap, phaseTapChangerFormValues, twtToModify) => {
-        const regulationMode =
-            phaseTapChangerFormValues?.[REGULATION_MODE] ??
-            getComputedPhaseTapChangerRegulationMode(twtToModify?.[PHASE_TAP_CHANGER])?.id;
-        const regulationType =
-            phaseTapChangerFormValues?.[REGULATION_TYPE] ?? getComputedPreviousPhaseRegulationType(twtToModify);
-        if (regulationMode) {
-            phaseTap.regulationType = toModificationOperation(phaseTapChangerFormValues?.[REGULATION_TYPE]);
-            if (regulationType === REGULATION_TYPES.LOCAL.id) {
-                phaseTap.regulationSide = toModificationOperation(phaseTapChangerFormValues?.[REGULATION_SIDE]);
-            } else if (regulationType === REGULATION_TYPES.DISTANT.id) {
-                phaseTap.terminalRefConnectableId = toModificationOperation(phaseTapChangerFormValues?.[EQUIPMENT]?.id);
-                phaseTap.terminalRefConnectableType = toModificationOperation(
-                    phaseTapChangerFormValues?.[EQUIPMENT]?.type
-                );
-                phaseTap.terminalRefConnectableVlId = toModificationOperation(
-                    phaseTapChangerFormValues?.[VOLTAGE_LEVEL]?.[ID]
+    const fillPhaseTapChangerRegulationAttributes = useCallback(
+        (
+            phaseTap: Record<string, unknown>,
+            phaseTapChangerFormValues: PhaseTapChangerFormSchema,
+            twtToModify: TwoWindingsTransformerMapInfos | null
+        ) => {
+            const regulationMode =
+                phaseTapChangerFormValues?.[REGULATION_MODE] ??
+                getComputedPhaseTapChangerRegulationMode(twtToModify?.[PHASE_TAP_CHANGER])?.id;
+            const regulationType =
+                phaseTapChangerFormValues?.[REGULATION_TYPE] ??
+                (twtToModify ? getComputedPreviousPhaseRegulationType(twtToModify) : undefined);
+            if (regulationMode) {
+                phaseTap.regulationType = toModificationOperation(phaseTapChangerFormValues?.[REGULATION_TYPE]);
+                if (regulationType === REGULATION_TYPES.LOCAL.id) {
+                    phaseTap.regulationSide = toModificationOperation(phaseTapChangerFormValues?.[REGULATION_SIDE]);
+                } else if (regulationType === REGULATION_TYPES.DISTANT.id) {
+                    phaseTap.terminalRefConnectableId = toModificationOperation(
+                        phaseTapChangerFormValues?.[EQUIPMENT]?.id
+                    );
+                    phaseTap.terminalRefConnectableType = toModificationOperation(
+                        phaseTapChangerFormValues?.[EQUIPMENT]?.type
+                    );
+                    phaseTap.terminalRefConnectableVlId = toModificationOperation(
+                        phaseTapChangerFormValues?.[VOLTAGE_LEVEL]?.[ID]
+                    );
+                }
+                phaseTap.regulationValue = toModificationOperation(
+                    computePhaseTapChangerRegulationValue(
+                        phaseTapChangerFormValues,
+                        twtToModify?.[PHASE_TAP_CHANGER]?.[REGULATION_MODE]
+                    )
                 );
+                phaseTap.targetDeadband = toModificationOperation(phaseTapChangerFormValues[TARGET_DEADBAND]);
             }
-            phaseTap.regulationValue = toModificationOperation(
-                computePhaseTapChangerRegulationValue(
-                    phaseTapChangerFormValues,
-                    twtToModify?.[PHASE_TAP_CHANGER]?.[REGULATION_MODE]
-                )
-            );
-            phaseTap.targetDeadband = toModificationOperation(phaseTapChangerFormValues[TARGET_DEADBAND]);
-        }
-    }, []);
-
-    const fillRatioTapChangerRegulationAttributes = useCallback((ratioTap, ratioTapChangerFormValues, twtToModify) => {
-        const hasLoadTapChangingCapabilities =
-            ratioTapChangerFormValues?.[LOAD_TAP_CHANGING_CAPABILITIES] ??
-            twtToModify?.[RATIO_TAP_CHANGER]?.[LOAD_TAP_CHANGING_CAPABILITIES];
-        const regulationType =
-            ratioTapChangerFormValues?.[REGULATION_TYPE] ?? getComputedPreviousRatioRegulationType(twtToModify);
-        if (hasLoadTapChangingCapabilities) {
-            ratioTap.regulationType = toModificationOperation(ratioTapChangerFormValues?.[REGULATION_TYPE]);
-            ratioTap.isRegulating = toModificationOperation(
-                ratioTapChangerFormValues?.[REGULATION_MODE]
-                    ? computeRatioTapChangerRegulating(ratioTapChangerFormValues)
-                    : null
-            );
-            if (regulationType === REGULATION_TYPES.LOCAL.id) {
-                ratioTap.regulationSide = toModificationOperation(ratioTapChangerFormValues?.[REGULATION_SIDE]);
-            } else if (regulationType === REGULATION_TYPES.DISTANT.id) {
-                ratioTap.terminalRefConnectableId = toModificationOperation(ratioTapChangerFormValues?.[EQUIPMENT]?.id);
-                ratioTap.terminalRefConnectableType = toModificationOperation(
-                    ratioTapChangerFormValues?.[EQUIPMENT]?.type
-                );
-                ratioTap.terminalRefConnectableVlId = toModificationOperation(
-                    ratioTapChangerFormValues?.[VOLTAGE_LEVEL]?.[ID]
+        },
+        []
+    );
+
+    const fillRatioTapChangerRegulationAttributes = useCallback(
+        (
+            ratioTap: Record<string, unknown>,
+            ratioTapChangerFormValues: RatioTapChangerFormSchema,
+            twtToModify: TwoWindingsTransformerMapInfos | null
+        ) => {
+            const hasLoadTapChangingCapabilities =
+                ratioTapChangerFormValues?.[LOAD_TAP_CHANGING_CAPABILITIES] ??
+                twtToModify?.[RATIO_TAP_CHANGER]?.[LOAD_TAP_CHANGING_CAPABILITIES];
+            const regulationType =
+                ratioTapChangerFormValues?.[REGULATION_TYPE] ??
+                (twtToModify ? getComputedPreviousRatioRegulationType(twtToModify) : undefined);
+            if (hasLoadTapChangingCapabilities) {
+                ratioTap.regulationType = toModificationOperation(ratioTapChangerFormValues?.[REGULATION_TYPE]);
+                ratioTap.isRegulating = toModificationOperation(
+                    ratioTapChangerFormValues?.[REGULATION_MODE]
+                        ? computeRatioTapChangerRegulating(ratioTapChangerFormValues)
+                        : null
                 );
+                if (regulationType === REGULATION_TYPES.LOCAL.id) {
+                    ratioTap.regulationSide = toModificationOperation(ratioTapChangerFormValues?.[REGULATION_SIDE]);
+                } else if (regulationType === REGULATION_TYPES.DISTANT.id) {
+                    ratioTap.terminalRefConnectableId = toModificationOperation(
+                        ratioTapChangerFormValues?.[EQUIPMENT]?.id
+                    );
+                    ratioTap.terminalRefConnectableType = toModificationOperation(
+                        ratioTapChangerFormValues?.[EQUIPMENT]?.type
+                    );
+                    ratioTap.terminalRefConnectableVlId = toModificationOperation(
+                        ratioTapChangerFormValues?.[VOLTAGE_LEVEL]?.[ID]
+                    );
+                }
+                ratioTap.targetV = toModificationOperation(ratioTapChangerFormValues?.[TARGET_V]);
+                ratioTap.targetDeadband = toModificationOperation(ratioTapChangerFormValues?.[TARGET_DEADBAND]);
             }
-            ratioTap.targetV = toModificationOperation(ratioTapChangerFormValues?.[TARGET_V]);
-            ratioTap.targetDeadband = toModificationOperation(ratioTapChangerFormValues?.[TARGET_DEADBAND]);
-        }
-    }, []);
+        },
+        []
+    );
 
     const computeRatioTapForSubmit = useCallback(
-        (twt) => {
-            let ratioTap;
+        (twt: TwoWindingsTransformerModificationFormValues): Record<string, unknown> => {
+            let ratioTap: Record<string, unknown>;
             const ratioTapChangerFormValues = twt[RATIO_TAP_CHANGER];
             const enableRatioTapChanger =
                 ratioTapChangerFormValues?.[ENABLED] !== !!twtToModify?.ratioTapChanger
@@ -394,10 +471,10 @@ const TwoWindingsTransformerModificationDialog = ({
                 isNodeBuilt(currentNode) && editData?.[RATIO_TAP_CHANGER]?.[STEPS]
                     ? true
                     : !compareStepsWithPreviousValues(
-                          ratioTapChangerFormValues[STEPS],
+                          ratioTapChangerFormValues?.[STEPS] as TapChangerStep[],
                           twtToModify?.[RATIO_TAP_CHANGER]?.[STEPS]
                       );
-            let ratioTapChangerSteps = !areRatioStepsModified ? null : ratioTapChangerFormValues[STEPS];
+            const ratioTapChangerSteps = !areRatioStepsModified ? null : ratioTapChangerFormValues?.[STEPS];
             if (ratioTapChangerFormValues?.[ENABLED]) {
                 ratioTap = {
                     [ENABLED]: toModificationOperation(enableRatioTapChanger),
@@ -420,8 +497,8 @@ const TwoWindingsTransformerModificationDialog = ({
     );
 
     const computePhaseTapForSubmit = useCallback(
-        (twt) => {
-            let phaseTap;
+        (twt: TwoWindingsTransformerModificationFormValues): Record<string, unknown> => {
+            let phaseTap: Record<string, unknown>;
             const phaseTapChangerFormValues = twt[PHASE_TAP_CHANGER];
             const enablePhaseTapChanger =
                 phaseTapChangerFormValues?.[ENABLED] !== !!twtToModify?.phaseTapChanger
@@ -431,10 +508,10 @@ const TwoWindingsTransformerModificationDialog = ({
                 isNodeBuilt(currentNode) && editData?.[PHASE_TAP_CHANGER]?.[STEPS]
                     ? true
                     : !compareStepsWithPreviousValues(
-                          phaseTapChangerFormValues[STEPS],
+                          phaseTapChangerFormValues?.[STEPS] as TapChangerStep[],
                           twtToModify?.[PHASE_TAP_CHANGER]?.[STEPS]
                       );
-            let phaseTapChangerSteps = !arePhaseStepsModified ? null : phaseTapChangerFormValues[STEPS];
+            const phaseTapChangerSteps = !arePhaseStepsModified ? null : phaseTapChangerFormValues?.[STEPS];
             if (phaseTapChangerFormValues?.[ENABLED]) {
                 phaseTap = {
                     [ENABLED]: toModificationOperation(enablePhaseTapChanger),
@@ -464,7 +541,7 @@ const TwoWindingsTransformerModificationDialog = ({
     );
 
     const onSubmit = useCallback(
-        (twt) => {
+        (twt: TwoWindingsTransformerModificationFormValues) => {
             const connectivity1 = twt[CONNECTIVITY]?.[CONNECTIVITY_1];
             const connectivity2 = twt[CONNECTIVITY]?.[CONNECTIVITY_2];
             const characteristics = twt[CHARACTERISTICS];
@@ -475,56 +552,58 @@ const TwoWindingsTransformerModificationDialog = ({
                 studyUuid: studyUuid,
                 nodeUuid: currentNodeUuid,
                 modificationUuid: editData?.uuid,
-                twoWindingsTransformerId: selectedId,
-                twoWindingsTransformerName: toModificationOperation(sanitizeString(twt[EQUIPMENT_NAME])),
-                r: toModificationOperation(characteristics[R]),
-                x: toModificationOperation(characteristics[X]),
-                g: toModificationOperation(convertOutputValue(FieldType.G, characteristics[G])),
-                b: toModificationOperation(convertOutputValue(FieldType.B, characteristics[B])),
-                ratedS: toModificationOperation(characteristics[RATED_S]),
-                ratedU1: toModificationOperation(characteristics[RATED_U1]),
-                ratedU2: toModificationOperation(characteristics[RATED_U2]),
-                operationalLimitsGroups: limits[ENABLE_OLG_MODIFICATION]
-                    ? addModificationTypeToOpLimitsGroups(limits[OPERATIONAL_LIMITS_GROUPS])
+                equipmentId: selectedId ?? '',
+                equipmentName: toModificationOperation(sanitizeString(twt[EQUIPMENT_NAME])),
+                r: toModificationOperation(characteristics?.[R]),
+                x: toModificationOperation(characteristics?.[X]),
+                g: toModificationOperation(convertOutputValue(FieldType.G, characteristics?.[G])),
+                b: toModificationOperation(convertOutputValue(FieldType.B, characteristics?.[B])),
+                ratedS: toModificationOperation(characteristics?.[RATED_S]),
+                ratedU1: toModificationOperation(characteristics?.[RATED_U1]),
+                ratedU2: toModificationOperation(characteristics?.[RATED_U2]),
+                operationalLimitsGroups: limits?.[ENABLE_OLG_MODIFICATION]
+                    ? (addModificationTypeToOpLimitsGroups(
+                          limits[OPERATIONAL_LIMITS_GROUPS] as OperationalLimitsGroupFormSchema[]
+                      ) as OperationalLimitsGroupModificationInfos[])
                     : [],
-                selectedLimitsGroup1: addOperationTypeToSelectedOpLG(
-                    limits[SELECTED_OPERATIONAL_LIMITS_GROUP_ID1],
+                selectedOperationalLimitsGroupId1: addOperationTypeToSelectedOpLG(
+                    limits?.[SELECTED_OPERATIONAL_LIMITS_GROUP_ID1],
                     intl.formatMessage({
                         id: 'None',
                     })
                 ),
-                selectedLimitsGroup2: addOperationTypeToSelectedOpLG(
-                    limits[SELECTED_OPERATIONAL_LIMITS_GROUP_ID2],
+                selectedOperationalLimitsGroupId2: addOperationTypeToSelectedOpLG(
+                    limits?.[SELECTED_OPERATIONAL_LIMITS_GROUP_ID2],
                     intl.formatMessage({
                         id: 'None',
                     })
                 ),
-                [ENABLE_OLG_MODIFICATION]: limits[ENABLE_OLG_MODIFICATION],
-                ratioTapChanger: computeRatioTapForSubmit(twt),
-                phaseTapChanger: computePhaseTapForSubmit(twt),
-                voltageLevelId1: connectivity1[VOLTAGE_LEVEL]?.id,
-                busOrBusbarSectionId1: connectivity1[BUS_OR_BUSBAR_SECTION]?.id,
-                voltageLevelId2: connectivity2[VOLTAGE_LEVEL]?.id,
-                busOrBusbarSectionId2: connectivity2[BUS_OR_BUSBAR_SECTION]?.id,
-                connectionName1: sanitizeString(connectivity1[CONNECTION_NAME]),
-                connectionName2: sanitizeString(connectivity2[CONNECTION_NAME]),
-                connectionDirection1: connectivity1[CONNECTION_DIRECTION],
-                connectionDirection2: connectivity2[CONNECTION_DIRECTION],
-                connectionPosition1: connectivity1[CONNECTION_POSITION],
-                connectionPosition2: connectivity2[CONNECTION_POSITION],
-                connected1: connectivity1[CONNECTED],
-                connected2: connectivity2[CONNECTED],
+                [ENABLE_OLG_MODIFICATION]: Boolean(limits?.[ENABLE_OLG_MODIFICATION]),
+                ratioTapChanger: computeRatioTapForSubmit(twt) as unknown as RatioTapChangerModificationInfos,
+                phaseTapChanger: computePhaseTapForSubmit(twt) as unknown as PhaseTapChangerModificationInfos,
+                voltageLevelId1: connectivity1?.[VOLTAGE_LEVEL]?.id,
+                busOrBusbarSectionId1: connectivity1?.[BUS_OR_BUSBAR_SECTION]?.id,
+                voltageLevelId2: connectivity2?.[VOLTAGE_LEVEL]?.id,
+                busOrBusbarSectionId2: connectivity2?.[BUS_OR_BUSBAR_SECTION]?.id,
+                connectionName1: sanitizeString(connectivity1?.[CONNECTION_NAME]),
+                connectionName2: sanitizeString(connectivity2?.[CONNECTION_NAME]),
+                connectionDirection1: connectivity1?.[CONNECTION_DIRECTION],
+                connectionDirection2: connectivity2?.[CONNECTION_DIRECTION],
+                connectionPosition1: connectivity1?.[CONNECTION_POSITION],
+                connectionPosition2: connectivity2?.[CONNECTION_POSITION],
+                terminal1Connected: connectivity1?.[CONNECTED],
+                terminal2Connected: connectivity2?.[CONNECTED],
                 properties: toModificationProperties(twt),
-                p1MeasurementValue: stateEstimationData[MEASUREMENT_P1][FieldConstants.VALUE],
-                p1MeasurementValidity: stateEstimationData[MEASUREMENT_P1][VALIDITY],
-                q1MeasurementValue: stateEstimationData[MEASUREMENT_Q1][FieldConstants.VALUE],
-                q1MeasurementValidity: stateEstimationData[MEASUREMENT_Q1][VALIDITY],
-                p2MeasurementValue: stateEstimationData[MEASUREMENT_P2][FieldConstants.VALUE],
-                p2MeasurementValidity: stateEstimationData[MEASUREMENT_P2][VALIDITY],
-                q2MeasurementValue: stateEstimationData[MEASUREMENT_Q2][FieldConstants.VALUE],
-                q2MeasurementValidity: stateEstimationData[MEASUREMENT_Q2][VALIDITY],
-                ratioTapChangerToBeEstimated: stateEstimationData[TO_BE_ESTIMATED][RATIO_TAP_CHANGER_STATUS],
-                phaseTapChangerToBeEstimated: stateEstimationData[TO_BE_ESTIMATED][PHASE_TAP_CHANGER_STATUS],
+                p1MeasurementValue: stateEstimationData?.[MEASUREMENT_P1]?.[FieldConstants.VALUE],
+                p1MeasurementValidity: stateEstimationData?.[MEASUREMENT_P1]?.[VALIDITY],
+                q1MeasurementValue: stateEstimationData?.[MEASUREMENT_Q1]?.[FieldConstants.VALUE],
+                q1MeasurementValidity: stateEstimationData?.[MEASUREMENT_Q1]?.[VALIDITY],
+                p2MeasurementValue: stateEstimationData?.[MEASUREMENT_P2]?.[FieldConstants.VALUE],
+                p2MeasurementValidity: stateEstimationData?.[MEASUREMENT_P2]?.[VALIDITY],
+                q2MeasurementValue: stateEstimationData?.[MEASUREMENT_Q2]?.[FieldConstants.VALUE],
+                q2MeasurementValidity: stateEstimationData?.[MEASUREMENT_Q2]?.[VALIDITY],
+                ratioTapChangerToBeEstimated: stateEstimationData?.[TO_BE_ESTIMATED]?.[RATIO_TAP_CHANGER_STATUS],
+                phaseTapChangerToBeEstimated: stateEstimationData?.[TO_BE_ESTIMATED]?.[PHASE_TAP_CHANGER_STATUS],
             }).catch((error) => {
                 snackWithFallback(snackError, error, { headerId: 'TwoWindingsTransformerModificationError' });
             });
@@ -541,8 +620,8 @@ const TwoWindingsTransformerModificationDialog = ({
         ]
     );
 
-    const onValidationError = (errors) => {
-        let tabsInError = [];
+    const onValidationError = (errors: FieldErrors<TwoWindingsTransformerModificationFormValues>) => {
+        const tabsInError: number[] = [];
         if (errors?.[CONNECTIVITY] !== undefined) {
             tabsInError.push(TwoWindingsTransformerModificationDialogTab.CONNECTIVITY_TAB);
         }
@@ -583,27 +662,27 @@ const TwoWindingsTransformerModificationDialog = ({
     });
 
     const isRatioTapChangerEnabled = useCallback(
-        (twt) => {
+        (twt: TwoWindingsTransformerMapInfos): boolean => {
             if (editData?.ratioTapChanger?.enabled === undefined) {
                 return !!twt.ratioTapChanger;
             }
-            return editData?.ratioTapChanger?.enabled?.value;
+            return editData?.ratioTapChanger?.enabled?.value ?? false;
         },
         [editData]
     );
 
     const isPhaseTapChangerEnabled = useCallback(
-        (twt) => {
+        (twt: TwoWindingsTransformerMapInfos): boolean => {
             if (editData?.phaseTapChanger?.enabled === undefined) {
                 return !!twt.phaseTapChanger;
             }
-            return editData?.phaseTapChanger?.enabled?.value;
+            return editData?.phaseTapChanger?.enabled?.value ?? false;
         },
         [editData?.phaseTapChanger?.enabled]
     );
 
     const getPhaseTapChangerSteps = useCallback(
-        (twt) => {
+        (twt: TwoWindingsTransformerMapInfos): TapChangerStep[] | undefined => {
             if (editData === undefined) {
                 return twt?.[PHASE_TAP_CHANGER]?.[STEPS];
             }
@@ -614,13 +693,13 @@ const TwoWindingsTransformerModificationDialog = ({
             ) {
                 return twt?.[PHASE_TAP_CHANGER]?.[STEPS];
             }
-            return editData?.phaseTapChanger?.steps;
+            return editData?.phaseTapChanger?.steps ?? undefined;
         },
         [editData]
     );
 
     const getRatioTapChangerSteps = useCallback(
-        (twt) => {
+        (twt: TwoWindingsTransformerMapInfos): TapChangerStep[] | undefined => {
             if (editData === undefined) {
                 return twt?.[RATIO_TAP_CHANGER]?.[STEPS];
             }
@@ -631,13 +710,13 @@ const TwoWindingsTransformerModificationDialog = ({
             ) {
                 return twt?.[RATIO_TAP_CHANGER]?.[STEPS];
             }
-            return editData?.ratioTapChanger?.steps;
+            return editData?.ratioTapChanger?.steps ?? undefined;
         },
         [editData]
     );
 
     const onEquipmentIdChange = useCallback(
-        (equipmentId) => {
+        (equipmentId: string | null) => {
             if (equipmentId) {
                 setDataFetchStatus(FetchStatus.RUNNING);
                 fetchNetworkElementInfos(
@@ -649,40 +728,40 @@ const TwoWindingsTransformerModificationDialog = ({
                     equipmentId,
                     true
                 )
-                    .then((twt) => {
+                    .then((twt: TwoWindingsTransformerMapInfos) => {
                         if (twt) {
                             setTwtToModify(twt);
+                            console.log('TWT form values', getValues());
                             reset(
                                 (formValues) => ({
                                     ...formValues,
                                     ...{
-                                        [LIMITS]: formValues?.limits[ENABLE_OLG_MODIFICATION]
+                                        [LIMITS]: (formValues?.limits?.[ENABLE_OLG_MODIFICATION]
                                             ? {
                                                   [ENABLE_OLG_MODIFICATION]: formValues.limits[ENABLE_OLG_MODIFICATION],
                                                   [OPERATIONAL_LIMITS_GROUPS]:
-                                                      getOpLimitsGroupInfosFromBranchModification(formValues),
+                                                      getOpLimitsGroupInfosFromBranchModification(
+                                                          formValues as LineModificationFormSchema
+                                                      ),
                                               }
                                             : {
                                                   [ENABLE_OLG_MODIFICATION]: false,
                                                   [OPERATIONAL_LIMITS_GROUPS]:
                                                       convertToOperationalLimitsGroupFormSchema(
-                                                          twt?.currentLimits ?? []
+                                                          (twt?.currentLimits ?? []) as CurrentLimitsData[]
                                                       ),
-                                              },
+                                              }) as LimitsFormSchema,
                                     },
                                     ...getRatioTapChangerFormData({
                                         enabled: isRatioTapChangerEnabled(twt),
                                         hasLoadTapChangingCapabilities: getValues(
                                             `${RATIO_TAP_CHANGER}.${LOAD_TAP_CHANGING_CAPABILITIES}`
                                         ),
-                                        regulationMode:
-                                            getValues(`${RATIO_TAP_CHANGER}.${REGULATING}`) === false
-                                                ? PHASE_REGULATION_MODES.OFF.id
-                                                : getValues(`${RATIO_TAP_CHANGER}.${REGULATION_MODE}`),
+                                        regulationMode: getValues(`${RATIO_TAP_CHANGER}.${REGULATION_MODE}`),
                                         regulationType: getValues(`${RATIO_TAP_CHANGER}.${REGULATION_TYPE}`),
                                         regulationSide: getValues(`${RATIO_TAP_CHANGER}.${REGULATION_SIDE}`),
-                                        targetV: getValues(`${RATIO_TAP_CHANGER}.${TARGET_V}`),
-                                        targetDeadband: getValues(`${RATIO_TAP_CHANGER}.${TARGET_DEADBAND}`),
+                                        targetV: getValues(`${RATIO_TAP_CHANGER}.${TARGET_V}`) as number,
+                                        targetDeadband: getValues(`${RATIO_TAP_CHANGER}.${TARGET_DEADBAND}`) as number,
                                         lowTapPosition: getValues(`${RATIO_TAP_CHANGER}.${LOW_TAP_POSITION}`),
                                         highTapPosition: getValues(`${RATIO_TAP_CHANGER}.${HIGH_TAP_POSITION}`),
                                         tapPosition: getValues(`${RATIO_TAP_CHANGER}.${TAP_POSITION}`),
@@ -711,7 +790,10 @@ const TwoWindingsTransformerModificationDialog = ({
                                         equipmentType: getValues(`${PHASE_TAP_CHANGER}.${EQUIPMENT}.${TYPE}`),
                                         voltageLevelId: getValues(`${PHASE_TAP_CHANGER}.${VOLTAGE_LEVEL}.${ID}`),
                                     }),
-                                    [FieldConstants.ADDITIONAL_PROPERTIES]: getConcatenatedProperties(twt, getValues),
+                                    [FieldConstants.ADDITIONAL_PROPERTIES]: getConcatenatedProperties(
+                                        twt as EquipmentWithProperties,
+                                        getValues
+                                    ),
                                 }),
                                 { keepDirty: true }
                             );
@@ -733,9 +815,9 @@ const TwoWindingsTransformerModificationDialog = ({
             studyUuid,
             currentNodeUuid,
             currentRootNetworkUuid,
-            getValues,
             reset,
             isRatioTapChangerEnabled,
+            getValues,
             getRatioTapChangerSteps,
             isPhaseTapChangerEnabled,
             getPhaseTapChangerSteps,
@@ -751,7 +833,10 @@ const TwoWindingsTransformerModificationDialog = ({
 
     const headerAndTabs = (
         <Grid container spacing={2}>
-            <TwoWindingsTransformerModificationDialogHeader equipmentToModify={twtToModify} equipmentId={selectedId} />
+            <TwoWindingsTransformerModificationDialogHeader
+                equipmentToModify={twtToModify?.name}
+                equipmentId={selectedId}
+            />
             <TwoWindingsTransformerModificationDialogTabs
                 tabIndex={tabIndex}
                 tabIndexesWithError={tabIndexesWithError}
@@ -763,7 +848,7 @@ const TwoWindingsTransformerModificationDialog = ({
     return (
         <CustomFormProvider
             removeOptional={true}
-            validationSchema={formSchema}
+            validationSchema={formSchema as any}
             {...formMethods}
             isNodeBuilt={isNodeBuilt(currentNode)}
             isUpdate={isUpdate}
@@ -801,7 +886,6 @@ const TwoWindingsTransformerModificationDialog = ({
                                 studyUuid={studyUuid}
                                 currentNode={currentNode}
                                 currentRootNetworkUuid={currentRootNetworkUuid}
-                                withPosition={true}
                                 isModification={true}
                                 previousValues={twtToModify}
                             />
@@ -818,7 +902,11 @@ const TwoWindingsTransformerModificationDialog = ({
                             <TwoWindingsTransformerCharacteristicsPane twtToModify={twtToModify} isModification />
                         </Box>
                         <Box hidden={tabIndex !== TwoWindingsTransformerModificationDialogTab.LIMITS_TAB} p={1}>
-                            <LimitsPane currentNode={currentNode} equipmentToModify={twtToModify} clearableFields />
+                            <LimitsPane
+                                currentNode={currentNode}
+                                equipmentToModify={twtToModify as BranchInfos}
+                                clearableFields
+                            />
                         </Box>
                         <Box
                             hidden={tabIndex !== TwoWindingsTransformerModificationDialogTab.STATE_ESTIMATION_TAB}
@@ -826,7 +914,7 @@ const TwoWindingsTransformerModificationDialog = ({
                         >
                             <Grid container spacing={2}>
                                 <BranchActiveReactivePowerMeasurementsForm equipmentToModify={twtToModify} />
-                                <ToBeEstimatedForm toBeEstimated={twtToModify?.toBeEstimated} />
+                                <ToBeEstimatedForm toBeEstimated={twtToModify?.toBeEstimated as ToBeEstimatedInfo} />
                             </Grid>
                         </Box>
                         <Box hidden={tabIndex !== TwoWindingsTransformerModificationDialogTab.RATIO_TAP_TAB} p={1}>
@@ -835,7 +923,7 @@ const TwoWindingsTransformerModificationDialog = ({
                                 currentNode={currentNode}
                                 currentRootNetworkUuid={currentRootNetworkUuid}
                                 voltageLevelOptions={voltageLevelOptions}
-                                previousValues={twtToModify}
+                                previousValues={twtToModify ?? undefined}
                                 editData={editData}
                                 isModification={true}
                             />
@@ -846,7 +934,7 @@ const TwoWindingsTransformerModificationDialog = ({
                                 currentNode={currentNode}
                                 currentRootNetworkUuid={currentRootNetworkUuid}
                                 voltageLevelOptions={voltageLevelOptions}
-                                previousValues={twtToModify}
+                                previousValues={twtToModify ?? undefined}
                                 editData={editData}
                                 isModification={true}
                             />
@@ -858,14 +946,4 @@ const TwoWindingsTransformerModificationDialog = ({
     );
 };
 
-TwoWindingsTransformerModificationDialog.propTypes = {
-    studyUuid: PropTypes.string,
-    defaultIdValue: PropTypes.string,
-    currentNode: PropTypes.object,
-    currentRootNetworkUuid: PropTypes.string,
-    isUpdate: PropTypes.bool,
-    editData: PropTypes.object,
-    editDataFetchStatus: PropTypes.string,
-};
-
 export default TwoWindingsTransformerModificationDialog;
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/phase-tap-changer-pane/phase-tap-changer-pane-steps.tsx b/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/phase-tap-changer-pane/phase-tap-changer-pane-steps.tsx
index 247b4337b8..f884844cbf 100644
--- a/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/phase-tap-changer-pane/phase-tap-changer-pane-steps.tsx
+++ b/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/phase-tap-changer-pane/phase-tap-changer-pane-steps.tsx
@@ -20,12 +20,13 @@ import { useIntl } from 'react-intl';
 import TapChangerSteps from '../tap-changer-steps';
 import { DndColumn, DndColumnType, parseIntData } from '@gridsuite/commons-ui';
 import { CurrentTreeNode } from 'components/graph/tree-node.type';
-import { PHASE_TAP, PhaseTapChangerData } from '../../two-windings-transformer.types';
+import { PHASE_TAP, TapChangerMapInfos } from '../../two-windings-transformer.types';
+import { TwoWindingsTransformerModificationInfo } from 'services/network-modification-types';
 
 export interface PhaseTapChangerPaneStepsProps {
     disabled?: boolean;
-    previousValues?: PhaseTapChangerData;
-    editData?: Record<string, unknown>;
+    previousValues?: TapChangerMapInfos;
+    editData?: TwoWindingsTransformerModificationInfo;
     currentNode: CurrentTreeNode;
     isModification?: boolean;
 }
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/phase-tap-changer-pane/phase-tap-changer-pane-utils.ts b/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/phase-tap-changer-pane/phase-tap-changer-pane-utils.ts
index 9e7208bb13..8734c164be 100644
--- a/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/phase-tap-changer-pane/phase-tap-changer-pane-utils.ts
+++ b/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/phase-tap-changer-pane/phase-tap-changer-pane-utils.ts
@@ -45,7 +45,11 @@ import {
     getRegulatingTerminalFormData,
 } from '../../../../regulating-terminal/regulating-terminal-form-utils';
 import { PHASE_REGULATION_MODES, REGULATION_TYPES, SIDE } from 'components/network/constants';
-import { TwoWindingsTransformerData, PhaseTapChangerData, TapChangerStep } from '../../two-windings-transformer.types';
+import {
+    TapChangerMapInfos,
+    TapChangerStep,
+    TwoWindingsTransformerMapInfos,
+} from '../../two-windings-transformer.types';
 
 const getRegulatingTerminalPhaseTapChangerValidationSchema = () => ({
     [VOLTAGE_LEVEL]: yup
@@ -163,6 +167,10 @@ const phaseTapChangerValidationSchema = (isModification: boolean, id: string) =>
     }),
 });
 
+export type PhaseTapChangerFormSchema = yup.InferType<
+    ReturnType<typeof phaseTapChangerValidationSchema>[typeof PHASE_TAP_CHANGER]
+>;
+
 export const getPhaseTapChangerValidationSchema = (isModification = false, id = PHASE_TAP_CHANGER) => {
     return phaseTapChangerValidationSchema(isModification, id);
 };
@@ -247,7 +255,7 @@ export const getPhaseTapChangerFormData = (
 type PhaseRegulationMode = (typeof PHASE_REGULATION_MODES)[keyof typeof PHASE_REGULATION_MODES] | undefined;
 
 export const getComputedPhaseTapChangerRegulationMode = (
-    phaseTapChangerFormValues?: PhaseTapChangerData
+    phaseTapChangerFormValues?: TapChangerMapInfos
 ): PhaseRegulationMode => {
     if (
         phaseTapChangerFormValues?.[REGULATION_MODE] === PHASE_REGULATION_MODES.OFF.id ||
@@ -270,7 +278,7 @@ export const getComputedPhaseTapChangerRegulationMode = (
     return undefined;
 };
 
-export const getPhaseTapRegulationSideId = (twt?: TwoWindingsTransformerData): string | null => {
+export const getPhaseTapRegulationSideId = (twt?: TwoWindingsTransformerMapInfos): string | null => {
     const phaseTapChangerValues = twt?.phaseTapChanger;
     if (!phaseTapChangerValues || !twt) {
         return null;
@@ -283,7 +291,7 @@ export const getPhaseTapRegulationSideId = (twt?: TwoWindingsTransformerData): s
 
 type RegulationType = (typeof REGULATION_TYPES)[keyof typeof REGULATION_TYPES] | null;
 
-export const getComputedPhaseRegulationType = (twt?: TwoWindingsTransformerData): RegulationType => {
+export const getComputedPhaseRegulationType = (twt?: TwoWindingsTransformerMapInfos): RegulationType => {
     if (!twt?.[PHASE_TAP_CHANGER]?.regulatingTerminalConnectableId) {
         return null;
     }
@@ -293,12 +301,14 @@ export const getComputedPhaseRegulationType = (twt?: TwoWindingsTransformerData)
     return REGULATION_TYPES.LOCAL;
 };
 
-export const getComputedPhaseRegulationTypeId = (twt?: TwoWindingsTransformerData): string | null => {
+export const getComputedPhaseRegulationTypeId = (twt?: TwoWindingsTransformerMapInfos): string | null => {
     const regulationType = getComputedPhaseRegulationType(twt);
     return regulationType?.id ?? null;
 };
 
-export const getComputedPreviousPhaseRegulationType = (previousValues?: TwoWindingsTransformerData): string | null => {
+export const getComputedPreviousPhaseRegulationType = (
+    previousValues?: TwoWindingsTransformerMapInfos
+): string | null => {
     const previousRegulationType = getComputedPhaseRegulationType(previousValues);
     return previousRegulationType?.id ?? null;
 };
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/phase-tap-changer-pane/phase-tap-changer-pane.tsx b/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/phase-tap-changer-pane/phase-tap-changer-pane.tsx
index 23b06b7842..1f67147aeb 100644
--- a/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/phase-tap-changer-pane/phase-tap-changer-pane.tsx
+++ b/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/phase-tap-changer-pane/phase-tap-changer-pane.tsx
@@ -28,7 +28,7 @@ import { useMemo } from 'react';
 import GridItem from '../../../../commons/grid-item';
 import GridSection from '../../../../commons/grid-section';
 import RegulatedTerminalSection from '../regulated-terminal-section';
-import { PhaseTapChangerData, PhaseTapChangerPaneProps } from '../../two-windings-transformer.types';
+import { TapChangerMapInfos, TapChangerPaneProps } from '../../two-windings-transformer.types';
 
 const PhaseTapChangerPane = ({
     id = PHASE_TAP_CHANGER,
@@ -39,7 +39,7 @@ const PhaseTapChangerPane = ({
     previousValues,
     editData,
     isModification = false,
-}: PhaseTapChangerPaneProps) => {
+}: TapChangerPaneProps) => {
     const intl = useIntl();
 
     const phaseTapChangerEnabledWatch = useWatch({
@@ -54,7 +54,7 @@ const PhaseTapChangerPane = ({
         name: `${id}.${REGULATION_TYPE}`,
     });
 
-    const getPhaseTapChangerRegulationModeLabel = (phaseTapChangerFormValues?: PhaseTapChangerData | null) => {
+    const getPhaseTapChangerRegulationModeLabel = (phaseTapChangerFormValues?: TapChangerMapInfos | null) => {
         const computedRegulationMode = getComputedPhaseTapChangerRegulationMode(phaseTapChangerFormValues ?? undefined);
         if (computedRegulationMode) {
             return intl.formatMessage({
@@ -63,7 +63,7 @@ const PhaseTapChangerPane = ({
         }
     };
 
-    const getRegulatingPreviousValue = (field: string, tap?: PhaseTapChangerData) => {
+    const getRegulatingPreviousValue = (field: string, tap?: TapChangerMapInfos) => {
         if (
             (tap?.[REGULATION_MODE] === PHASE_REGULATION_MODES.ACTIVE_POWER_CONTROL.id &&
                 field === FLOW_SET_POINT_REGULATING_VALUE) ||
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/ratio-tap-changer-pane/ratio-tap-changer-pane-steps.tsx b/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/ratio-tap-changer-pane/ratio-tap-changer-pane-steps.tsx
index 3c67df0508..6183513134 100644
--- a/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/ratio-tap-changer-pane/ratio-tap-changer-pane-steps.tsx
+++ b/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/ratio-tap-changer-pane/ratio-tap-changer-pane-steps.tsx
@@ -19,11 +19,11 @@ import { useIntl } from 'react-intl';
 import { DndColumn, DndColumnType, parseIntData } from '@gridsuite/commons-ui';
 import { CurrentTreeNode } from 'components/graph/tree-node.type';
 import TapChangerSteps from '../tap-changer-steps';
-import { RATIO_TAP, RatioTapChangerData } from '../../two-windings-transformer.types';
+import { RATIO_TAP, TapChangerMapInfos } from '../../two-windings-transformer.types';
 
 export interface RatioTapChangerPaneStepsProps {
     disabled?: boolean;
-    previousValues?: RatioTapChangerData;
+    previousValues?: TapChangerMapInfos;
     editData?: Record<string, unknown>;
     currentNode: CurrentTreeNode;
     isModification?: boolean;
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/ratio-tap-changer-pane/ratio-tap-changer-pane-utils.ts b/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/ratio-tap-changer-pane/ratio-tap-changer-pane-utils.ts
index af0c55944d..f55bbabab5 100644
--- a/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/ratio-tap-changer-pane/ratio-tap-changer-pane-utils.ts
+++ b/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/ratio-tap-changer-pane/ratio-tap-changer-pane-utils.ts
@@ -41,7 +41,7 @@ import {
     getRegulatingTerminalFormData,
 } from '../../../../regulating-terminal/regulating-terminal-form-utils';
 import { RATIO_REGULATION_MODES, REGULATION_TYPES, SIDE } from 'components/network/constants';
-import { TapChangerStep, TwoWindingsTransformerData } from '../../two-windings-transformer.types';
+import { TapChangerStep, TwoWindingsTransformerMapInfos } from '../../two-windings-transformer.types';
 import { TwtEquipmentInfos } from 'components/tooltips/equipment-popover-type';
 
 const getRegulatingTerminalRatioTapChangerValidationSchema = () => ({
@@ -183,6 +183,10 @@ const ratioTapChangerValidationSchema = (isModification: boolean, id: string) =>
     }),
 });
 
+export type RatioTapChangerFormSchema = yup.InferType<
+    ReturnType<typeof ratioTapChangerValidationSchema>[typeof RATIO_TAP_CHANGER]
+>;
+
 export const getRatioTapChangerValidationSchema = (isModification = false, id = RATIO_TAP_CHANGER) => {
     return ratioTapChangerValidationSchema(isModification, id);
 };
@@ -264,7 +268,7 @@ export const getRatioTapChangerFormData = (
     },
 });
 
-export const getComputedRegulationType = (twt: TwoWindingsTransformerData) => {
+export const getComputedRegulationType = (twt: TwoWindingsTransformerMapInfos) => {
     if (
         !twt?.[RATIO_TAP_CHANGER]?.[LOAD_TAP_CHANGING_CAPABILITIES] ||
         !twt?.[RATIO_TAP_CHANGER]?.regulatingTerminalConnectableId
@@ -278,12 +282,12 @@ export const getComputedRegulationType = (twt: TwoWindingsTransformerData) => {
     }
 };
 
-export const getComputedRegulationTypeId = (twt: TwoWindingsTransformerData) => {
+export const getComputedRegulationTypeId = (twt: TwoWindingsTransformerMapInfos) => {
     const regulationType = getComputedRegulationType(twt);
     return regulationType?.id || null;
 };
 
-export const getComputedRegulationMode = (twt: TwoWindingsTransformerData | TwtEquipmentInfos) => {
+export const getComputedRegulationMode = (twt: TwoWindingsTransformerMapInfos | TwtEquipmentInfos) => {
     const ratioTapChangerValues = twt?.ratioTapChanger;
     if (!ratioTapChangerValues) {
         return null;
@@ -295,7 +299,7 @@ export const getComputedRegulationMode = (twt: TwoWindingsTransformerData | TwtE
     }
 };
 
-export const getInitialTwtRatioRegulationModeId = (twt: TwoWindingsTransformerData) => {
+export const getInitialTwtRatioRegulationModeId = (twt: TwoWindingsTransformerMapInfos) => {
     // if onLoadTapChangingCapabilities is set to false or undefined, we set the regulation mode to null
     if (!twt?.ratioTapChanger?.hasLoadTapChangingCapabilities) {
         return null;
@@ -305,16 +309,16 @@ export const getInitialTwtRatioRegulationModeId = (twt: TwoWindingsTransformerDa
     return computedRegulationMode?.id || null;
 };
 
-export const getComputedRegulationModeId = (twt: TwoWindingsTransformerData) => {
+export const getComputedRegulationModeId = (twt: TwoWindingsTransformerMapInfos) => {
     return getComputedRegulationMode(twt)?.id || null;
 };
 
-export const getComputedPreviousRatioRegulationType = (previousValues: TwoWindingsTransformerData) => {
+export const getComputedPreviousRatioRegulationType = (previousValues: TwoWindingsTransformerMapInfos) => {
     const previousRegulationType = getComputedRegulationType(previousValues);
     return previousRegulationType?.id || null;
 };
 
-export const getComputedTapSide = (twt: TwoWindingsTransformerData) => {
+export const getComputedTapSide = (twt: TwoWindingsTransformerMapInfos) => {
     const ratioTapChangerValues = twt?.ratioTapChanger;
     if (!ratioTapChangerValues || !twt) {
         return null;
@@ -326,6 +330,6 @@ export const getComputedTapSide = (twt: TwoWindingsTransformerData) => {
     }
 };
 
-export const getComputedTapSideId = (twt: TwoWindingsTransformerData) => {
+export const getComputedTapSideId = (twt: TwoWindingsTransformerMapInfos) => {
     return getComputedTapSide(twt)?.id || null;
 };
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/ratio-tap-changer-pane/ratio-tap-changer-pane.tsx b/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/ratio-tap-changer-pane/ratio-tap-changer-pane.tsx
index 6eda483d3f..e8102998e0 100644
--- a/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/ratio-tap-changer-pane/ratio-tap-changer-pane.tsx
+++ b/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/ratio-tap-changer-pane/ratio-tap-changer-pane.tsx
@@ -35,9 +35,9 @@ import GridItem from '../../../../commons/grid-item';
 import GridSection from '../../../../commons/grid-section';
 import RegulatedTerminalSection from '../regulated-terminal-section';
 import {
-    TwoWindingsTransformerData,
-    RatioTapChangerData,
-    RatioTapChangerPaneProps,
+    TapChangerMapInfos,
+    TapChangerPaneProps,
+    TwoWindingsTransformerMapInfos,
 } from '../../two-windings-transformer.types';
 
 const RatioTapChangerPane = ({
@@ -49,7 +49,7 @@ const RatioTapChangerPane = ({
     previousValues,
     editData,
     isModification = false,
-}: RatioTapChangerPaneProps) => {
+}: TapChangerPaneProps) => {
     const { trigger, setValue, getValues } = useFormContext();
     const intl = useIntl();
 
@@ -63,7 +63,7 @@ const RatioTapChangerPane = ({
         return undefined;
     };
 
-    const getRatioTapChangerRegulationModeLabel = (ratioTapChangerFormValues?: RatioTapChangerData | null) => {
+    const getRatioTapChangerRegulationModeLabel = (ratioTapChangerFormValues?: TapChangerMapInfos | null) => {
         if (!ratioTapChangerFormValues) {
             return undefined;
         }
@@ -104,7 +104,7 @@ const RatioTapChangerPane = ({
     }, [previousValues, regulationTypeWatch]);
 
     const findAndSetVoltageLevelFromPrevious = useCallback(
-        (previousValues: TwoWindingsTransformerData | undefined, voltageLevelOptions: Identifiable[]) => {
+        (previousValues: TwoWindingsTransformerMapInfos | undefined, voltageLevelOptions: Identifiable[]) => {
             const prevVl = voltageLevelOptions.find(
                 (vl) => vl.id === previousValues?.ratioTapChanger?.regulatingTerminalVlId
             );
@@ -123,7 +123,7 @@ const RatioTapChangerPane = ({
     );
 
     const setEquipmentFromPrevious = useCallback(
-        (previousValues: TwoWindingsTransformerData | undefined) => {
+        (previousValues: TwoWindingsTransformerMapInfos | undefined) => {
             const prevEquipmentId = previousValues?.ratioTapChanger?.regulatingTerminalConnectableId;
             if (prevEquipmentId) {
                 const prevEquipmentType = previousValues?.ratioTapChanger?.regulatingTerminalConnectableType;
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/tap-changer-steps.tsx b/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/tap-changer-steps.tsx
index 2d556e46d3..e48838c871 100644
--- a/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/tap-changer-steps.tsx
+++ b/src/components/dialogs/network-modifications/two-windings-transformer/tap-changer-pane/tap-changer-steps.tsx
@@ -33,7 +33,7 @@ import { compareStepsWithPreviousValues, computeHighTapPosition } from 'componen
 import { isNodeBuilt } from 'components/graph/util/model-functions';
 import { transformIfFrenchNumber } from '../../tabular/tabular-common.js';
 import { CurrentTreeNode } from 'components/graph/tree-node.type';
-import { RuleType, TapChangerData, TapChangerStep } from '../two-windings-transformer.types';
+import { RuleType, TapChangerMapInfos, TapChangerStep } from '../two-windings-transformer.types';
 
 export interface TapChangerStepsProps {
     tapChanger: string;
@@ -47,7 +47,7 @@ export interface TapChangerStepsProps {
     resetButtonMessageId: string;
     handleImportRow: (val: Record<string, string>) => Record<string, string | number>;
     disabled?: boolean;
-    previousValues?: TapChangerData;
+    previousValues?: TapChangerMapInfos;
     editData?: Record<string, unknown>;
     currentNode: CurrentTreeNode;
     isModification?: boolean;
diff --git a/src/components/dialogs/network-modifications/two-windings-transformer/two-windings-transformer.types.ts b/src/components/dialogs/network-modifications/two-windings-transformer/two-windings-transformer.types.ts
index a9166c2486..1b9c32ed7d 100644
--- a/src/components/dialogs/network-modifications/two-windings-transformer/two-windings-transformer.types.ts
+++ b/src/components/dialogs/network-modifications/two-windings-transformer/two-windings-transformer.types.ts
@@ -4,13 +4,32 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
  */
-
-import { Identifiable } from '@gridsuite/commons-ui';
+import { Identifiable, FieldConstants } from '@gridsuite/commons-ui';
 import { CurrentTreeNode } from 'components/graph/tree-node.type';
 import {
-    ENABLED,
+    B,
+    BUS_OR_BUSBAR_SECTION,
+    CONNECTED,
+    CONNECTION_DIRECTION,
+    CONNECTION_NAME,
+    CONNECTION_POSITION,
+    CONNECTIVITY_1,
+    CONNECTIVITY_2,
+    G,
     HIGH_TAP_POSITION,
+    ID,
+    LOAD_TAP_CHANGING_CAPABILITIES,
     LOW_TAP_POSITION,
+    MEASUREMENT_P1,
+    MEASUREMENT_P2,
+    MEASUREMENT_Q1,
+    MEASUREMENT_Q2,
+    PHASE_TAP_CHANGER_STATUS,
+    R,
+    RATED_S,
+    RATED_U1,
+    RATED_U2,
+    RATIO_TAP_CHANGER_STATUS,
     REGULATING,
     REGULATING_TERMINAL_CONNECTABLE_ID,
     REGULATING_TERMINAL_CONNECTABLE_TYPE,
@@ -28,15 +47,110 @@ import {
     STEPS_TAP,
     TAP_POSITION,
     TARGET_DEADBAND,
+    TARGET_V,
+    TO_BE_ESTIMATED,
+    VALIDITY,
+    VOLTAGE_LEVEL,
+    X,
 } from 'components/utils/field-constants';
 import { UUID } from 'node:crypto';
+import { ConnectablePositionFormInfos } from 'components/dialogs/connectivity/connectivity.type';
+import { LimitsProperty, TwoWindingsTransformerModificationInfo } from 'services/network-modification-types';
 
 export const PHASE_TAP = 'dephasing';
 export const RATIO_TAP = 'ratio';
 
 export type RuleType = typeof PHASE_TAP | typeof RATIO_TAP;
 
-export interface TapChangerStep {
+export interface TapChangerStep extends TapChangerStepMapInfos {
+    [SELECTED]?: boolean;
+}
+
+export interface TapChangerPaneProps {
+    id?: string;
+    studyUuid: UUID;
+    currentNode: CurrentTreeNode;
+    currentRootNetworkUuid: UUID;
+    voltageLevelOptions?: Identifiable[];
+    previousValues?: TwoWindingsTransformerMapInfos;
+    editData?: TwoWindingsTransformerModificationInfo;
+    isModification?: boolean;
+}
+
+// Creation/Modification form types
+export interface EntityIdReference {
+    [ID]: string;
+}
+
+export type ConnectivityFormSchema = {
+    [VOLTAGE_LEVEL]: EntityIdReference | null;
+    [BUS_OR_BUSBAR_SECTION]: EntityIdReference | null;
+    [CONNECTION_DIRECTION]: string | null;
+    [CONNECTION_NAME]: string;
+    [CONNECTION_POSITION]: number | null;
+    [CONNECTED]: boolean | null;
+};
+
+export type CharacteristicsFormSchema = {
+    [R]: number | null;
+    [X]: number | null;
+    [G]: number | null;
+    [B]: number | null;
+    [RATED_S]: number | null;
+    [RATED_U1]: number | null;
+    [RATED_U2]: number | null;
+};
+export type CharacteristicsCreationFormSchema = CharacteristicsFormSchema & {
+    [CONNECTIVITY_1]: ConnectivityFormSchema;
+    [CONNECTIVITY_2]: ConnectivityFormSchema;
+};
+
+export interface MeasurementFormSchema {
+    [FieldConstants.VALUE]: number | null;
+    [VALIDITY]: boolean | null;
+}
+
+export interface ToBeEstimatedFormSchema {
+    [RATIO_TAP_CHANGER_STATUS]: boolean | null;
+    [PHASE_TAP_CHANGER_STATUS]: boolean | null;
+}
+
+export interface StateEstimationFormSchema {
+    [MEASUREMENT_P1]: MeasurementFormSchema;
+    [MEASUREMENT_Q1]: MeasurementFormSchema;
+    [MEASUREMENT_P2]: MeasurementFormSchema;
+    [MEASUREMENT_Q2]: MeasurementFormSchema;
+    [TO_BE_ESTIMATED]: ToBeEstimatedFormSchema;
+}
+
+// Types from network map server response
+
+interface TwoWindingsTransformerToBeEstimatedInfos {
+    ratioTapChangerStatus?: boolean;
+    phaseTapChangerStatus?: boolean;
+}
+
+interface MeasurementsInfos {
+    value?: number;
+    validity: boolean;
+}
+
+export interface TemporaryLimitMapInfos {
+    name: string;
+    value?: number;
+    acceptableDuration?: number;
+}
+
+export interface CurrentLimitsMapInfos {
+    id?: string;
+    permanentLimit?: number;
+    temporaryLimits?: TemporaryLimitMapInfos[];
+    temporaryLimitsByName?: Record<string, TemporaryLimitMapInfos>;
+    applicability: string;
+    limitsProperties?: LimitsProperty[];
+}
+
+export interface TapChangerStepMapInfos {
     [STEPS_RESISTANCE]: number;
     [STEPS_REACTANCE]: number;
     [STEPS_CONDUCTANCE]: number;
@@ -44,53 +158,58 @@ export interface TapChangerStep {
     [STEPS_RATIO]: number;
     [STEPS_ALPHA]?: number;
     [STEPS_TAP]?: number;
-    [SELECTED]?: boolean;
 }
 
-export interface TapChangerData {
-    [ENABLED]?: boolean;
-    [HIGH_TAP_POSITION]?: number;
+export interface TapChangerMapInfos {
+    [LOW_TAP_POSITION]: number;
+    [TAP_POSITION]: number;
+    [HIGH_TAP_POSITION]: number;
     [REGULATING]?: boolean;
-    [LOW_TAP_POSITION]?: number;
-    [REGULATING_TERMINAL_CONNECTABLE_ID]?: string;
-    [REGULATING_TERMINAL_CONNECTABLE_TYPE]?: string;
-    [REGULATING_TERMINAL_VOLTAGE_LEVEL_ID]?: string;
-    [STEPS]?: TapChangerStep[];
-    [TAP_POSITION]?: number;
+    [LOAD_TAP_CHANGING_CAPABILITIES]?: boolean;
+    [TARGET_V]?: number;
     [TARGET_DEADBAND]?: number;
-}
-
-export interface RatioTapChangerData extends TapChangerData {
-    hasLoadTapChangingCapabilities?: boolean;
-    loadTapChangingCapabilities?: boolean;
-    targetV?: number | null;
-}
-
-export interface PhaseTapChangerData extends TapChangerData {
     [REGULATION_MODE]?: string;
     [REGULATION_VALUE]?: number;
+    [REGULATING_TERMINAL_CONNECTABLE_ID]?: string;
+    [REGULATING_TERMINAL_CONNECTABLE_TYPE]?: string;
+    [REGULATING_TERMINAL_VOLTAGE_LEVEL_ID]?: string;
+    [STEPS]?: TapChangerStepMapInfos[];
 }
 
-export interface TapChangerPaneProps {
-    id?: string;
-    studyUuid: UUID;
-    currentNode: CurrentTreeNode;
-    currentRootNetworkUuid: UUID;
-    voltageLevelOptions?: Identifiable[];
-    previousValues?: TwoWindingsTransformerData;
-    editData?: Record<string, unknown>;
-    isModification?: boolean;
-}
-
-export type PhaseTapChangerPaneProps = TapChangerPaneProps;
-export type RatioTapChangerPaneProps = TapChangerPaneProps;
-
-export interface TwoWindingsTransformerData {
-    id?: string;
-    name?: string;
-    voltageLevelId1?: string;
-    voltageLevelId2?: string;
-    ratioTapChanger?: RatioTapChangerData;
-    phaseTapChanger?: PhaseTapChangerData;
-    [key: string]: unknown;
+export interface TwoWindingsTransformerMapInfos extends Identifiable {
+    properties?: Record<string, string>;
+    voltageLevelId1: string;
+    voltageLevelName1: string;
+    voltageLevelId2: string;
+    voltageLevelName2: string;
+    terminal1Connected: boolean;
+    terminal2Connected: boolean;
+    p1?: number;
+    q1?: number;
+    p2?: number;
+    q2?: number;
+    i1?: number;
+    i2?: number;
+    currentLimits?: CurrentLimitsMapInfos[];
+    selectedOperationalLimitsGroupId1?: string;
+    selectedOperationalLimitsGroupId2?: string;
+    phaseTapChanger?: TapChangerMapInfos;
+    ratioTapChanger?: TapChangerMapInfos;
+    g: number;
+    b: number;
+    r: number;
+    x: number;
+    ratedU1: number;
+    ratedU2: number;
+    ratedS?: number;
+    connectablePosition1: ConnectablePositionFormInfos;
+    connectablePosition2: ConnectablePositionFormInfos;
+    busOrBusbarSectionId1?: string;
+    busOrBusbarSectionId2?: string;
+    operatingStatus?: string;
+    measurementP1?: MeasurementsInfos;
+    measurementQ1?: MeasurementsInfos;
+    measurementP2?: MeasurementsInfos;
+    measurementQ2?: MeasurementsInfos;
+    toBeEstimated?: TwoWindingsTransformerToBeEstimatedInfos;
 }
diff --git a/src/components/utils/utils.ts b/src/components/utils/utils.ts
index 4ad76de94a..ac7da733bb 100644
--- a/src/components/utils/utils.ts
+++ b/src/components/utils/utils.ts
@@ -294,10 +294,12 @@ export function arrayFrom(start = 0.0, stop = 0.0, step = 1.0) {
     return Array.from({ length }, (_, index) => start + index * step);
 }
 
-export const addSelectedFieldToRows = <T>(rows: T[]): (T & { selected: boolean })[] => {
-    return rows?.map((row) => {
-        return { ...row, [SELECTED]: false };
-    });
+export const addSelectedFieldToRows = <T>(rows?: T[]): (T & { selected: boolean })[] => {
+    return (
+        rows?.map((row) => {
+            return { ...row, [SELECTED]: false };
+        }) ?? []
+    );
 };
 
 //Escapes regex special characters to avoid misinterpreting user prompts
diff --git a/src/services/network-modification-types.ts b/src/services/network-modification-types.ts
index 1f6c668660..4274bc1545 100644
--- a/src/services/network-modification-types.ts
+++ b/src/services/network-modification-types.ts
@@ -221,12 +221,57 @@ export interface StaticVarCompensatorCreationInfo {
     properties?: Property[] | null;
 }
 
+export interface TapChangerModificationInfos {
+    enabled: AttributeModification<boolean> | null;
+    regulationType: AttributeModification<string> | null;
+    regulationSide: AttributeModification<string> | null;
+    lowTapPosition: AttributeModification<number> | null;
+    tapPosition: AttributeModification<number> | null;
+    isRegulating: AttributeModification<boolean> | null;
+    targetDeadband: AttributeModification<number> | null;
+    terminalRefConnectableId: AttributeModification<string> | null;
+    terminalRefConnectableType: AttributeModification<string> | null;
+    terminalRefConnectableVlId: AttributeModification<string> | null;
+    steps: TapChangerStepCreationInfos[] | null;
+    hasLoadTapChangingCapabilities: AttributeModification<boolean> | null;
+}
+
+export interface RatioTapChangerModificationInfos extends TapChangerModificationInfos {
+    targetV: AttributeModification<number> | null;
+}
+
+export interface PhaseTapChangerModificationInfos extends TapChangerModificationInfos {
+    regulationMode: AttributeModification<string> | null;
+    regulationValue: AttributeModification<number> | null;
+}
+
+export interface CurrentTemporaryLimitModificationInfos {
+    name: AttributeModification<string> | null;
+    value: AttributeModification<number> | null;
+    acceptableDuration: AttributeModification<number> | null;
+    modificationType: string | null;
+}
+
+export interface CurrentLimitsModificationInfos {
+    permanentLimit: number | null;
+    temporaryLimits: CurrentTemporaryLimitModificationInfos[] | null;
+}
+
+export interface OperationalLimitsGroupModificationInfos {
+    id: string;
+    currentLimits: CurrentLimitsModificationInfos | null;
+    modificationType?: string | null;
+    temporaryLimitsModificationType?: string | null;
+    limitsProperties?: LimitsPropertyInfos[] | null;
+    applicability: string | null;
+}
+
 export interface TwoWindingsTransformerModificationInfo {
     studyUuid: string;
     nodeUuid: UUID;
     modificationUuid?: string;
-    twoWindingsTransformerId: string;
-    twoWindingsTransformerName: AttributeModification<string> | null;
+    equipmentId: string;
+    equipmentName: AttributeModification<string> | null;
     r: AttributeModification<number> | null;
     x: AttributeModification<number> | null;
     g: AttributeModification<number> | null;
@@ -234,35 +279,39 @@ export interface TwoWindingsTransformerModificationInfo {
     ratedS: AttributeModification<number> | null;
     ratedU1: AttributeModification<number> | null;
     ratedU2: AttributeModification<number> | null;
-    operationalLimitsGroups: OperationalLimitsGroup[];
-    selectedLimitsGroup1: string;
-    selectedLimitsGroup2: string;
+    selectedOperationalLimitsGroupId1: AttributeModification<string> | null;
+    selectedOperationalLimitsGroupId2: AttributeModification<string> | null;
     [ENABLE_OLG_MODIFICATION]: boolean;
-    voltageLevelId1?: string;
-    busOrBusbarSectionId1?: string;
-    voltageLevelId2?: string;
-    busOrBusbarSectionId2?: string;
-    ratioTapChanger: Record<string, any> | null;
-    phaseTapChanger: Record<string, any> | null;
+    voltageLevelId1?: string | null;
+    busOrBusbarSectionId1?: string | null;
+    voltageLevelId2?: string | null;
+    busOrBusbarSectionId2?: string | null;
     connectionName1?: string | null;
     connectionDirection1?: string | null;
     connectionName2?: string | null;
     connectionDirection2?: string | null;
-    connectionPosition1?: string | null;
-    connectionPosition2?: string | null;
-    connected1?: boolean;
-    connected2?: boolean;
-    properties: Property[];
-    p1MeasurementValue: number | null;
-    p1MeasurementValidity: boolean | null;
-    q1MeasurementValue: number | null;
-    q1MeasurementValidity: boolean | null;
-    p2MeasurementValue: number | null;
-    p2MeasurementValidity: boolean | null;
-    q2MeasurementValue: number | null;
-    q2MeasurementValidity: boolean | null;
-    ratioTapChangerToBeEstimated: boolean | null;
-    phaseTapChangerToBeEstimated: boolean | null;
+    connectionPosition1?: number | null;
+    connectionPosition2?: number | null;
+    terminal1Connected?: boolean | null;
+    terminal2Connected?: boolean | null;
+    properties: Property[] | null;
+    p1MeasurementValue?: number | null;
+    p1MeasurementValidity?: boolean | null;
+    q1MeasurementValue?: number | null;
+    q1MeasurementValidity?: boolean | null;
+    p2MeasurementValue?: number | null;
+    p2MeasurementValidity?: boolean | null;
+    q2MeasurementValue?: number | null;
+    q2MeasurementValidity?: boolean | null;
+    ratioTapChangerToBeEstimated?: boolean | null;
+    phaseTapChangerToBeEstimated?: boolean | null;
+
+    operationalLimitsGroupsModificationType?: string | null;
+    operationalLimitsGroups: OperationalLimitsGroupModificationInfos[] | null;
+    ratioTapChanger: RatioTapChangerModificationInfos | null;
+    phaseTapChanger: PhaseTapChangerModificationInfos | null;
+    uuid?: string;
+    activated?: boolean | null;
 }
 
 export interface OperationalLimitsGroup {
@@ -591,29 +640,77 @@ export interface LineModificationInfos {
     q2MeasurementValidity: boolean | null;
 }
 
+export interface LimitsPropertyInfos {
+    name: string;
+    value: string;
+}
+
+export interface CurrentTemporaryLimitCreationInfos {
+    name: string | null;
+    value: number | null;
+    acceptableDuration: number | null;
+}
+
+export interface CurrentLimitsInfos {
+    permanentLimit: number | null;
+    temporaryLimits: CurrentTemporaryLimitCreationInfos[] | null;
+}
+
+export interface OperationalLimitsGroupInfos {
+    id: string | null;
+    currentLimits: CurrentLimitsInfos | null;
+    applicability: string | null;
+    limitsProperties?: LimitsPropertyInfos[] | null;
+}
+
+export interface TapChangerStepCreationInfos {
+    index: number;
+    rho: number;
+    r: number;
+    x: number;
+    g: number;
+    b: number;
+    alpha?: number;
+}
+export interface TapChangerCreationInfos {
+    lowTapPosition: number;
+    tapPosition: number;
+    isRegulating: boolean;
+    targetDeadband: number | null;
+    terminalRefConnectableId: string | null;
+    terminalRefConnectableType: string | null;
+    terminalRefConnectableVlId: string | null;
+    steps: TapChangerStepCreationInfos[];
+    hasLoadTapChangingCapabilities: boolean;
+}
+
+export interface RatioTapChangerCreationInfos extends TapChangerCreationInfos {
+    targetV: number | null;
+}
+
+export interface PhaseTapChangerCreationInfos extends TapChangerCreationInfos {
+    regulationMode: string | null;
+    regulationValue: number | null;
+}
+
 export interface TwoWindingsTransformerCreationInfo {
     studyUuid: string;
     nodeUuid: UUID;
     isUpdate: boolean;
-    modificationUuid: string;
-    twoWindingsTransformerId: string;
-    twoWindingsTransformerName: string | null;
-    r: number;
+    uuid: string;
+    equipmentId: string;
+    equipmentName: string | null;
+    r: number | null;
     x: number;
     g: number;
     b: number;
     ratedS: number | null;
     ratedU1: number;
     ratedU2: number;
-    limitsGroups: OperationalLimitsGroup[];
-    selectedLimitsGroup1: string;
-    selectedLimitsGroup2: string;
     voltageLevelId1: string;
     busOrBusbarSectionId1: string;
     voltageLevelId2: string;
     busOrBusbarSectionId2: string;
-    ratioTapChanger: any;
-    phaseTapChanger: any;
     connectionName1: string | null;
     connectionDirection1: string | null;
     connectionName2: string | null;
@@ -623,6 +720,13 @@ export interface TwoWindingsTransformerCreationInfo {
     connected1: boolean;
     connected2: boolean;
     properties: Property[] | null;
+
+    ratioTapChanger: RatioTapChangerCreationInfos | null;
+    phaseTapChanger: PhaseTapChangerCreationInfos | null;
+
+    operationalLimitsGroups: OperationalLimitsGroupInfos[] | null;
+    selectedOperationalLimitsGroupId1: string | null;
+    selectedOperationalLimitsGroupId2: string | null;
 }
 
 export interface AttachedSubstationCreationInfo {
diff --git a/src/services/study/network-modifications.ts b/src/services/study/network-modifications.ts
index e3389e2e4b..57ad022bf8 100644
--- a/src/services/study/network-modifications.ts
+++ b/src/services/study/network-modifications.ts
@@ -845,8 +845,8 @@ export function modifyLine({
 export function createTwoWindingsTransformer({
     studyUuid,
     nodeUuid,
-    twoWindingsTransformerId,
-    twoWindingsTransformerName,
+    equipmentId,
+    equipmentName,
     r,
     x,
     g,
@@ -854,9 +854,9 @@ export function createTwoWindingsTransformer({
     ratedS,
     ratedU1,
     ratedU2,
-    limitsGroups,
-    selectedLimitsGroup1,
-    selectedLimitsGroup2,
+    operationalLimitsGroups,
+    selectedOperationalLimitsGroupId1,
+    selectedOperationalLimitsGroupId2,
     voltageLevelId1,
     busOrBusbarSectionId1,
     voltageLevelId2,
@@ -864,7 +864,7 @@ export function createTwoWindingsTransformer({
     ratioTapChanger,
     phaseTapChanger,
     isUpdate,
-    modificationUuid,
+    uuid,
     connectionName1,
     connectionDirection1,
     connectionName2,
@@ -878,7 +878,7 @@ export function createTwoWindingsTransformer({
     let createTwoWindingsTransformerUrl = getNetworkModificationUrl(studyUuid, nodeUuid);
 
     if (isUpdate) {
-        createTwoWindingsTransformerUrl += '/' + encodeURIComponent(modificationUuid);
+        createTwoWindingsTransformerUrl += '/' + encodeURIComponent(uuid);
         console.info('Updating two windings transformer creation');
     } else {
         console.info('Creating two windings transformer creation');
@@ -892,8 +892,8 @@ export function createTwoWindingsTransformer({
         },
         body: JSON.stringify({
             type: MODIFICATION_TYPES.TWO_WINDINGS_TRANSFORMER_CREATION.type,
-            equipmentId: twoWindingsTransformerId,
-            equipmentName: twoWindingsTransformerName,
+            equipmentId,
+            equipmentName,
             r: r,
             x: x,
             g: g,
@@ -901,9 +901,9 @@ export function createTwoWindingsTransformer({
             ratedS: ratedS,
             ratedU1: ratedU1,
             ratedU2: ratedU2,
-            operationalLimitsGroups: limitsGroups,
-            selectedOperationalLimitsGroupId1: selectedLimitsGroup1,
-            selectedOperationalLimitsGroupId2: selectedLimitsGroup2,
+            operationalLimitsGroups,
+            selectedOperationalLimitsGroupId1,
+            selectedOperationalLimitsGroupId2,
             voltageLevelId1: voltageLevelId1,
             busOrBusbarSectionId1: busOrBusbarSectionId1,
             voltageLevelId2: voltageLevelId2,
@@ -927,8 +927,8 @@ export function modifyTwoWindingsTransformer({
     studyUuid,
     nodeUuid,
     modificationUuid = undefined,
-    twoWindingsTransformerId,
-    twoWindingsTransformerName,
+    equipmentId,
+    equipmentName,
     r,
     x,
     g,
@@ -937,8 +937,8 @@ export function modifyTwoWindingsTransformer({
     ratedU1,
     ratedU2,
     operationalLimitsGroups,
-    selectedLimitsGroup1,
-    selectedLimitsGroup2,
+    selectedOperationalLimitsGroupId1,
+    selectedOperationalLimitsGroupId2,
     enableOLGModification,
     ratioTapChanger,
     phaseTapChanger,
@@ -952,8 +952,8 @@ export function modifyTwoWindingsTransformer({
     connectionDirection2 = undefined,
     connectionPosition1 = undefined,
     connectionPosition2 = undefined,
-    connected1 = undefined,
-    connected2 = undefined,
+    terminal1Connected = undefined,
+    terminal2Connected = undefined,
     properties: propertiesForBackend,
     p1MeasurementValue,
     p1MeasurementValidity,
@@ -984,8 +984,8 @@ export function modifyTwoWindingsTransformer({
         },
         body: JSON.stringify({
             type: MODIFICATION_TYPES.TWO_WINDINGS_TRANSFORMER_MODIFICATION.type,
-            equipmentId: twoWindingsTransformerId,
-            equipmentName: twoWindingsTransformerName,
+            equipmentId,
+            equipmentName,
             r: r,
             x: x,
             g: g,
@@ -994,8 +994,8 @@ export function modifyTwoWindingsTransformer({
             ratedU1: ratedU1,
             ratedU2: ratedU2,
             operationalLimitsGroups: operationalLimitsGroups,
-            selectedOperationalLimitsGroupId1: selectedLimitsGroup1,
-            selectedOperationalLimitsGroupId2: selectedLimitsGroup2,
+            selectedOperationalLimitsGroupId1,
+            selectedOperationalLimitsGroupId2,
             [ENABLE_OLG_MODIFICATION]: enableOLGModification,
             [OLGS_MODIFICATION_TYPE]: enableOLGModification
                 ? OPERATIONAL_LIMITS_GROUPS_MODIFICATION_TYPE.REPLACE
@@ -1012,8 +1012,8 @@ export function modifyTwoWindingsTransformer({
             connectionDirection2: toModificationOperation(connectionDirection2),
             connectionPosition1: toModificationOperation(connectionPosition1),
             connectionPosition2: toModificationOperation(connectionPosition2),
-            terminal1Connected: toModificationOperation(connected1),
-            terminal2Connected: toModificationOperation(connected2),
+            terminal1Connected: toModificationOperation(terminal1Connected),
+            terminal2Connected: toModificationOperation(terminal2Connected),
             properties: propertiesForBackend,
             p1MeasurementValue: toModificationOperation(p1MeasurementValue),
             p1MeasurementValidity: toModificationOperation(p1MeasurementValidity),