diff --git a/api/src/backend/api/models.py b/api/src/backend/api/models.py
index 4c85044f9d..d1387a4216 100644
--- a/api/src/backend/api/models.py
+++ b/api/src/backend/api/models.py
@@ -58,6 +58,7 @@ from api.rls import (
     Tenant,
 )
 from prowler.lib.check.models import Severity
+from prowler.providers.common.provider import Provider as SDKProvider
 
 fernet = Fernet(settings.SECRETS_ENCRYPTION_KEY.encode())
 
@@ -501,13 +502,24 @@ class Provider(RowLevelSecurityProtectedModel):
 
     def clean(self):
         super().clean()
+        if self.provider not in SDKProvider.get_available_providers():
+            raise ModelValidationError(
+                detail=f"{self.provider} is not a supported provider.",
+                code="invalid",
+                pointer="/data/attributes/provider",
+            )
         if self.provider == self.ProviderChoices.OKTA and self.uid:
             # Mirror the SDK, which lowercases the org domain before connecting.
             # Without this the API would reject Acme.okta.com even though the
             # SDK would accept it, and stored uids could disagree with the
             # authenticated org domain.
             self.uid = self.uid.strip().lower()
-        getattr(self, f"validate_{self.provider}_uid")(self.uid)
+        # Providers the SDK exposes but the API has no specific uid rule for
+        # (e.g. external providers) fall back to the field-level min-length
+        # check only, instead of failing on a missing validator.
+        uid_validator = getattr(self, f"validate_{self.provider}_uid", None)
+        if uid_validator is not None:
+            uid_validator(self.uid)
 
     def save(self, *args, **kwargs):
         self.full_clean()
diff --git a/api/src/backend/api/tests/test_models.py b/api/src/backend/api/tests/test_models.py
index b8b7f61dd1..4a71eba00e 100644
--- a/api/src/backend/api/tests/test_models.py
+++ b/api/src/backend/api/tests/test_models.py
@@ -6,7 +6,9 @@ from django.core.exceptions import ValidationError
 from django.db import IntegrityError
 
 from api.db_router import MainRouter
+from api.exceptions import ModelValidationError
 from api.models import (
+    Provider,
     ProviderComplianceScore,
     Resource,
     ResourceTag,
@@ -525,3 +527,29 @@ class TestTenantComplianceSummaryModel:
 
         assert summary1.id != summary2.id
         assert summary1.requirements_passed != summary2.requirements_passed
+
+
+@pytest.mark.django_db
+class TestProviderDynamicValidation:
+    """Provider validity is driven by the SDK's available providers, not a
+    static enum. Providers the SDK exposes are accepted; for those without a
+    `validate_<provider>_uid` method only the uid min-length floor applies."""
+
+    def test_accepts_provider_without_uid_validator(self, tenants_fixture):
+        tenant = tenants_fixture[0]
+        provider = Provider.objects.create(
+            tenant_id=tenant.id, provider="llm", uid="my-llm-account"
+        )
+        assert provider.provider == "llm"
+
+    def test_rejects_provider_not_available_in_sdk(self, tenants_fixture):
+        tenant = tenants_fixture[0]
+        with pytest.raises(ModelValidationError):
+            Provider.objects.create(
+                tenant_id=tenant.id, provider="does-not-exist", uid="whatever"
+            )
+
+    def test_uid_floor_still_enforced_for_external_provider(self, tenants_fixture):
+        tenant = tenants_fixture[0]
+        with pytest.raises(ValidationError):
+            Provider.objects.create(tenant_id=tenant.id, provider="llm", uid="ab")
diff --git a/api/src/backend/api/tests/test_serializers.py b/api/src/backend/api/tests/test_serializers.py
index 5810a97b63..cdba488932 100644
--- a/api/src/backend/api/tests/test_serializers.py
+++ b/api/src/backend/api/tests/test_serializers.py
@@ -2,7 +2,27 @@ import pytest
 from rest_framework.exceptions import ValidationError
 
 from api.v1.serializer_utils.integrations import S3ConfigSerializer
-from api.v1.serializers import ImageProviderSecret
+from api.v1.serializers import ImageProviderSecret, ProviderEnumSerializerField
+
+
+class TestProviderEnumSerializerField:
+    """The provider field accepts whatever the SDK exposes (built-in or
+    external) and rejects anything else with `invalid_choice`."""
+
+    def test_accepts_sdk_available_provider(self):
+        field = ProviderEnumSerializerField()
+        assert field.run_validation("aws") == "aws"
+
+    def test_accepts_external_provider_absent_from_static_enum(self):
+        field = ProviderEnumSerializerField()
+        # `llm` is exposed by the SDK but is not part of the legacy static enum.
+        assert field.run_validation("llm") == "llm"
+
+    def test_rejects_unknown_provider(self):
+        field = ProviderEnumSerializerField()
+        with pytest.raises(ValidationError) as exc:
+            field.run_validation("does-not-exist")
+        assert exc.value.detail[0].code == "invalid_choice"
 
 
 class TestS3ConfigSerializer:
diff --git a/api/src/backend/api/v1/serializers.py b/api/src/backend/api/v1/serializers.py
index d085edea0c..03c4a99e7e 100644
--- a/api/src/backend/api/v1/serializers.py
+++ b/api/src/backend/api/v1/serializers.py
@@ -73,6 +73,7 @@ from api.v1.serializer_utils.lighthouse import (
 from api.v1.serializer_utils.processors import ProcessorConfigField
 from api.v1.serializer_utils.providers import ProviderSecretField
 from prowler.lib.mutelist.mutelist import Mutelist
+from prowler.providers.common.provider import Provider as SDKProvider
 
 # Base
 
@@ -854,7 +855,12 @@ class ProviderGroupMembershipSerializer(RLSSerializer, BaseWriteSerializer):
 # Providers
 class ProviderEnumSerializerField(serializers.ChoiceField):
     def __init__(self, **kwargs):
-        kwargs["choices"] = Provider.ProviderChoices.choices
+        # The SDK is the source of truth for which providers exist, so the
+        # accepted values track the installed providers (built-in or external)
+        # instead of a static enum.
+        kwargs["choices"] = [
+            (name, name) for name in SDKProvider.get_available_providers()
+        ]
         super().__init__(**kwargs)