diff --git a/edc_consent/modelform_mixins/consent_modelform_mixin/consent_modelform_validation_mixin.py b/edc_consent/modelform_mixins/consent_modelform_mixin/consent_modelform_validation_mixin.py
index 2ae9177..e047c9c 100644
--- a/edc_consent/modelform_mixins/consent_modelform_mixin/consent_modelform_validation_mixin.py
+++ b/edc_consent/modelform_mixins/consent_modelform_mixin/consent_modelform_validation_mixin.py
@@ -7,11 +7,9 @@
 from django import forms
 from edc_constants.constants import NO, YES
 from edc_model_form.utils import get_field_or_raise
-from edc_sites.site import sites as site_sites
 from edc_utils import AgeValueError, age, formatted_age
 
-from ...exceptions import SiteConsentError
-from ...site_consents import ConsentDefinitionDoesNotExist, site_consents
+from ...exceptions import ConsentDefinitionValidityPeriodError
 from ...utils import InvalidInitials, verify_initials_against_full_name
 
 if TYPE_CHECKING:
@@ -29,23 +27,17 @@ class ConsentModelFormValidationMixin:
 
     @property
     def consent_definition(self) -> ConsentDefinition:
-        """Returns a ConsentDefinition instance or raises on
-        missing data.
+        """Returns a ConsentDefinition instance or raises
+        if consent date not within consent definition validity
+        period.
         """
-        current_site_id = getattr(
-            self.instance.site, "id", site_sites.get_current_site().site_id
-        )
-        try:
-            consent_definition = site_consents.get_consent_definition(
-                model=self._meta.model._meta.label_lower,
-                report_datetime=self.consent_datetime,
-                site=site_sites.get(current_site_id),
-            )
-        except (ConsentDefinitionDoesNotExist, SiteConsentError) as e:
-            raise forms.ValidationError(e)
-        if not consent_definition.version:
-            raise forms.ValidationError("Unable to determine consent version")
-        return consent_definition
+        cdef: ConsentDefinition = self.subject_screening.consent_definition
+        if self.consent_datetime:
+            try:
+                cdef.valid_for_datetime_or_raise(self.consent_datetime)
+            except ConsentDefinitionValidityPeriodError as e:
+                raise forms.ValidationError({"consent_datetime": str(e)})
+        return cdef
 
     def get_field_or_raise(self, name: str, msg: str) -> Any:
         return get_field_or_raise(
diff --git a/edc_consent/modelform_mixins/requires_consent_modelform_mixin.py b/edc_consent/modelform_mixins/requires_consent_modelform_mixin.py
index 7e4f7c0..2964602 100644
--- a/edc_consent/modelform_mixins/requires_consent_modelform_mixin.py
+++ b/edc_consent/modelform_mixins/requires_consent_modelform_mixin.py
@@ -9,6 +9,7 @@
 from edc_utils.date import to_local, to_utc
 from edc_visit_schedule.site_visit_schedules import site_visit_schedules
 
+from .. import NotConsentedError
 from ..exceptions import ConsentDefinitionDoesNotExist
 
 if TYPE_CHECKING:
@@ -38,6 +39,8 @@ def validate_against_consent(self) -> None:
                 model_obj = self.get_consent_or_raise()
             except ConsentDefinitionDoesNotExist as e:
                 raise forms.ValidationError(e)
+            except NotConsentedError as e:
+                raise forms.ValidationError(e)
             else:
                 if floor_secs(to_utc(self.report_datetime)) < floor_secs(
                     model_obj.consent_datetime
diff --git a/edc_consent/tests/models.py b/edc_consent/tests/models.py
index 35949bf..a681981 100644
--- a/edc_consent/tests/models.py
+++ b/edc_consent/tests/models.py
@@ -17,10 +17,16 @@
     ReviewFieldsMixin,
     VulnerabilityFieldsMixin,
 )
-from edc_consent.model_mixins import ConsentModelMixin, RequiresConsentFieldsModelMixin
+from edc_consent.model_mixins import (
+    ConsentDefinitionModelMixin,
+    ConsentModelMixin,
+    RequiresConsentFieldsModelMixin,
+)
+
 
+class SubjectScreening(SiteModelMixin, ConsentDefinitionModelMixin, BaseUuidModel):
+    consent_definition = None
 
-class SubjectScreening(SiteModelMixin, BaseUuidModel):
     screening_identifier = models.CharField(max_length=25, unique=True)
 
     initials = models.CharField(max_length=5, default="TO")
diff --git a/edc_consent/tests/tests/test_consent_form.py b/edc_consent/tests/tests/test_consent_form.py
index 8c9af20..fc1c813 100644
--- a/edc_consent/tests/tests/test_consent_form.py
+++ b/edc_consent/tests/tests/test_consent_form.py
@@ -55,17 +55,19 @@ def setUp(self):
         self.study_open_datetime = ResearchProtocolConfig().study_open_datetime
         self.study_close_datetime = ResearchProtocolConfig().study_close_datetime
 
-        self.consent_factory(
+        self.convent_v1 = self.consent_factory(
             start=self.study_open_datetime,
             end=self.study_open_datetime + timedelta(days=50),
             version="1.0",
         )
-        self.consent_factory(
+        SubjectScreening.consent_definition = self.convent_v1
+
+        self.convent_v2 = self.consent_factory(
             start=self.study_open_datetime + timedelta(days=51),
             end=self.study_open_datetime + timedelta(days=100),
             version="2.0",
         )
-        self.consent_factory(
+        self.convent_v3 = self.consent_factory(
             start=self.study_open_datetime + timedelta(days=101),
             end=self.study_open_datetime + timedelta(days=150),
             version="3.0",