diff --git a/service_oriented/application/config/base_config.py b/service_oriented/application/config/base_config.py
index 9f9af0c..eb317e0 100644
--- a/service_oriented/application/config/base_config.py
+++ b/service_oriented/application/config/base_config.py
@@ -1,7 +1,14 @@
-from typing import Any, Optional
+from typing import Any, Optional, Tuple, Type
 
-from pydantic_settings import BaseSettings, SettingsConfigDict
+from pydantic_settings import (
+    BaseSettings,
+    PydanticBaseSettingsSource,
+    SettingsConfigDict,
+)
 
+from service_oriented.application.config.yaml_config_settings_source import (
+    YamlConfigSettingsSource,
+)
 from service_oriented.deployment_environment import DeploymentEnvironment
 
 
@@ -9,6 +16,7 @@ class BaseConfig(BaseSettings):
     model_config = SettingsConfigDict()
 
     deployment_environment: DeploymentEnvironment
+    yaml_config_path: Optional[str] = None
 
     def __init__(self, *args: Any, **kwargs: Any):
         if not self.model_config.get("env_nested_delimiter"):
@@ -18,3 +26,30 @@ def __init__(self, *args: Any, **kwargs: Any):
             raise RuntimeError("env_prefix model config is required")
 
         super().__init__(*args, **kwargs)
+
+    @classmethod
+    def settings_customise_sources(
+        cls,
+        settings_cls: Type[BaseSettings],
+        init_settings: PydanticBaseSettingsSource,
+        env_settings: PydanticBaseSettingsSource,
+        dotenv_settings: PydanticBaseSettingsSource,
+        file_secret_settings: PydanticBaseSettingsSource,
+    ) -> Tuple[PydanticBaseSettingsSource, ...]:
+        yaml_config_settings = YamlConfigSettingsSource.from_sources(
+            settings_cls=settings_cls,
+            sources=[
+                init_settings,
+                env_settings,
+                file_secret_settings,
+                dotenv_settings,
+            ],
+        )
+
+        return (
+            init_settings,
+            env_settings,
+            file_secret_settings,
+            yaml_config_settings,
+            dotenv_settings,
+        )
diff --git a/service_oriented_test/application/config/base_config_test.py b/service_oriented_test/application/config/base_config_test.py
index e4ec493..1fafca5 100644
--- a/service_oriented_test/application/config/base_config_test.py
+++ b/service_oriented_test/application/config/base_config_test.py
@@ -1,3 +1,6 @@
+import os
+from tempfile import NamedTemporaryFile, TemporaryDirectory
+
 import pytest
 from pydantic import ValidationError
 from pydantic_settings import SettingsConfigDict
@@ -14,21 +17,10 @@
 )
 
 
-class ConfigWithoutEnvPrefix(BaseConfig):
-    model_config = SettingsConfigDict(env_nested_delimiter="__")
-
-
 class ConfigWithoutEnvNestedDelimiter(BaseConfig):
     model_config = SettingsConfigDict(env_prefix="prefix_")
 
 
-class ConfigWithAllTheThings(BaseConfig):
-    model_config = SettingsConfigDict(
-        env_nested_delimiter="__",
-        env_prefix="test_",
-    )
-
-
 def test_env_nested_delimiter_is_required() -> None:
     with pytest.raises(RuntimeError) as exinfo:
         ConfigWithoutEnvNestedDelimiter(
@@ -39,6 +31,10 @@ def test_env_nested_delimiter_is_required() -> None:
     assert "env_nested_delimiter model config is required" == exception_message
 
 
+class ConfigWithoutEnvPrefix(BaseConfig):
+    model_config = SettingsConfigDict(env_nested_delimiter="__")
+
+
 def test_env_prefix_is_required() -> None:
     with pytest.raises(RuntimeError) as exinfo:
         ConfigWithoutEnvPrefix(deployment_environment=TEST_DEPLOYMENT_ENVIRONMENT)
@@ -47,6 +43,13 @@ def test_env_prefix_is_required() -> None:
     assert "env_prefix model config is required" == exception_message
 
 
+class ConfigWithAllTheThings(BaseConfig):
+    model_config = SettingsConfigDict(
+        env_nested_delimiter="__",
+        env_prefix="base_config_test_",
+    )
+
+
 def test_deployment_environment_is_accessible() -> None:
     config = ConfigWithAllTheThings(
         deployment_environment=TEST_DEPLOYMENT_ENVIRONMENT,
@@ -63,3 +66,71 @@ def test_deployment_environment_is_required() -> None:
     assert "1 validation error for ConfigWithAllTheThings" in exception_message
     assert "deployment_environment" in exception_message
     assert "Field required" in exception_message
+
+
+def test_yaml_config_path_is_accessible() -> None:
+    yaml_config_path = "foo"
+    config = ConfigWithAllTheThings(
+        deployment_environment=TEST_DEPLOYMENT_ENVIRONMENT,
+        yaml_config_path=yaml_config_path,
+    )
+    assert yaml_config_path == config.yaml_config_path
+
+
+def test_yaml_config_path_is_optional() -> None:
+    config = ConfigWithAllTheThings(
+        deployment_environment=TEST_DEPLOYMENT_ENVIRONMENT,
+    )
+    assert config.yaml_config_path is None
+
+
+class ConfigForTestingSourcePriorities(ConfigWithAllTheThings):
+    layer_one: str
+    layer_two: str
+    layer_three: str
+    layer_four: str
+    layer_five: str
+
+
+def test_setting_source_priorities() -> None:
+    os.environ["BASE_CONFIG_TEST_LAYER_ONE"] = "env"
+    os.environ["BASE_CONFIG_TEST_LAYER_TWO"] = "env"
+    with TemporaryDirectory() as secrets_dir:
+        for config_name in ["layer_one", "layer_two", "layer_three"]:
+            with open(
+                f"{secrets_dir}/base_config_test_{config_name}", "w+"
+            ) as secret_file:
+                secret_file.write("secret")
+        with NamedTemporaryFile(mode="w+") as yaml_file:
+            yaml_file.write(
+                """
+                layer_one: yaml
+                layer_two: yaml
+                layer_three: yaml
+                layer_four: yaml
+                """
+            )
+            yaml_file.flush()
+            with NamedTemporaryFile(mode="w+") as dotenv_file:
+                dotenv_file.write(
+                    """
+                    BASE_CONFIG_TEST_LAYER_ONE=dotenv
+                    BASE_CONFIG_TEST_LAYER_TWO=dotenv
+                    BASE_CONFIG_TEST_LAYER_THREE=dotenv
+                    BASE_CONFIG_TEST_LAYER_FOUR=dotenv
+                    BASE_CONFIG_TEST_LAYER_FIVE=dotenv
+                    """
+                )
+                dotenv_file.flush()
+                config = ConfigForTestingSourcePriorities(
+                    _env_file=dotenv_file.name,
+                    _secrets_dir=secrets_dir,
+                    layer_one="init",
+                    deployment_environment=TEST_DEPLOYMENT_ENVIRONMENT,
+                    yaml_config_path=yaml_file.name,
+                )
+                assert "init" == config.layer_one
+                assert "env" == config.layer_two
+                assert "secret" == config.layer_three
+                assert "yaml" == config.layer_four
+                assert "dotenv" == config.layer_five