diff --git a/src/registrar/admin.py b/src/registrar/admin.py
index 1476cee7e..52e214bb9 100644
--- a/src/registrar/admin.py
+++ b/src/registrar/admin.py
@@ -2003,6 +2003,9 @@ class DomainRequestAdmin(ListHeaderAdmin, ImportExportModelAdmin):
 
     custom_requested_domain.admin_order_field = "requested_domain__name"  # type: ignore
 
+    # ------ Converted fields ------
+    # These fields map to @Property methods and
+    # require these custom definitions to work properly
     @admin.display(description=_("Generic Org Type"))
     def converted_generic_org_type(self, obj):
         return obj.converted_generic_org_type_display
diff --git a/src/registrar/assets/src/js/getgov-admin/domain-request-form.js b/src/registrar/assets/src/js/getgov-admin/domain-request-form.js
index d82b2de8b..b3d14839e 100644
--- a/src/registrar/assets/src/js/getgov-admin/domain-request-form.js
+++ b/src/registrar/assets/src/js/getgov-admin/domain-request-form.js
@@ -645,7 +645,6 @@ function handleSuborgFieldsAndButtons() {
     const suborganizationCity = document.getElementById("id_suborganization_city");
     const suborganizationStateTerritory = document.getElementById("id_suborganization_state_territory");
     const rejectButton = document.querySelector("#clear-requested-suborganization");
-    console.log("test12345678")
 
     // Ensure that every variable is present before proceeding
     if (!requestedSuborganizationField || !suborganizationCity || !suborganizationStateTerritory || !rejectButton) {
diff --git a/src/registrar/assets/src/js/getgov-admin/helpers-portfolio-dynamic-fields.js b/src/registrar/assets/src/js/getgov-admin/helpers-portfolio-dynamic-fields.js
index 55b42d10d..9a60e1684 100644
--- a/src/registrar/assets/src/js/getgov-admin/helpers-portfolio-dynamic-fields.js
+++ b/src/registrar/assets/src/js/getgov-admin/helpers-portfolio-dynamic-fields.js
@@ -495,6 +495,7 @@ export function handlePortfolioSelection(
             if (requestedSuborganizationField) hideElement(requestedSuborganizationField);
             if (suborganizationCity) hideElement(suborganizationCity);
             if (suborganizationStateTerritory) hideElement(suborganizationStateTerritory);
+
             // == LOGIC FOR THE DOMAIN REQUEST PAGE == //
             if (rejectSuborganizationButton) hideElement(rejectSuborganizationButton);  
         }
diff --git a/src/registrar/models/domain.py b/src/registrar/models/domain.py
index 003714dfb..6eb2fac07 100644
--- a/src/registrar/models/domain.py
+++ b/src/registrar/models/domain.py
@@ -244,7 +244,6 @@ class Domain(TimeStampedModel, DomainHelper):
         is called in the validate function on the request/domain page
 
         throws- RegistryError or InvalidDomainError"""
-        return True
         if not cls.string_could_be_domain(domain):
             logger.warning("Not a valid domain: %s" % str(domain))
             # throw invalid domain error so that it can be caught in
diff --git a/src/registrar/models/domain_request.py b/src/registrar/models/domain_request.py
index f4e2a35a1..533a22ced 100644
--- a/src/registrar/models/domain_request.py
+++ b/src/registrar/models/domain_request.py
@@ -697,10 +697,18 @@ class DomainRequest(TimeStampedModel):
                     portfolio__isnull=False,
                 ).exists()
             ):
-                raise ValidationError(
+                # Add a field-level error to requested_suborganization.
+                # To pass in field-specific errors, we need to embed a dict of
+                # field: validationerror then pass that into a validation error itself.
+                # This is slightly confusing, but it just adds it at that level.
+                msg = (
                     "This suborganization already exists. "
                     "Choose a new name, or select it directly if you would like to use it."
                 )
+                errors = { 
+                    "requested_suborganization": ValidationError(msg)
+                }
+                raise ValidationError(errors)
         elif self.portfolio and not self.sub_organization:
             # You cannot create a new suborganization without these fields
             required_suborg_fields = {
@@ -708,16 +716,16 @@ class DomainRequest(TimeStampedModel):
                 "suborganization_city": self.suborganization_city,
                 "suborganization_state_territory": self.suborganization_state_territory,
             }
-
+            # If at least one value is populated, enforce a all-or-nothing rule
             if any(bool(value) for value in required_suborg_fields.values()):
-                # Find which fields are empty
-                errors_dict = {
-                    field_name: [f"This field is required when creating a new suborganization."]
-                    for field_name, value in required_suborg_fields.items()
-                    if not value
-                }
-                # Adds a validation error to each missing field
-                raise ValidationError({k: ValidationError(v, code="required") for k, v in errors_dict.items()})
+                # Find which fields are empty and throw an error on the field
+                errors = {}
+                for field_name, value in required_suborg_fields.items():
+                    if not value:
+                        errors[field_name] = ValidationError(
+                            "This field is required when creating a new suborganization.",
+                        )
+                raise ValidationError(errors)
 
     def save(self, *args, **kwargs):
         """Save override for custom properties"""
diff --git a/src/registrar/tests/test_admin_request.py b/src/registrar/tests/test_admin_request.py
index 439f4fab0..a294c127f 100644
--- a/src/registrar/tests/test_admin_request.py
+++ b/src/registrar/tests/test_admin_request.py
@@ -1,5 +1,7 @@
 from datetime import datetime
+from django.forms import ValidationError
 from django.utils import timezone
+from waffle.testutils import override_flag
 import re
 from django.test import RequestFactory, Client, TestCase, override_settings
 from django.contrib.admin.sites import AdminSite
@@ -25,6 +27,7 @@ from registrar.models import (
     Portfolio,
     AllowedEmail,
 )
+from registrar.models.suborganization import Suborganization
 from .common import (
     MockSESClient,
     completed_domain_request,
@@ -82,6 +85,7 @@ class TestDomainRequestAdmin(MockEppLib):
         Contact.objects.all().delete()
         Website.objects.all().delete()
         SeniorOfficial.objects.all().delete()
+        Suborganization.objects.all().delete()
         Portfolio.objects.all().delete()
         self.mock_client.EMAILS_SENT.clear()
 
@@ -91,6 +95,99 @@ class TestDomainRequestAdmin(MockEppLib):
         User.objects.all().delete()
         AllowedEmail.objects.all().delete()
 
+    @override_flag("organization_feature", active=True)
+    @less_console_noise_decorator
+    def test_clean_validates_duplicate_suborganization(self):
+        """Tests that clean() prevents duplicate suborganization names within the same portfolio"""
+        # Create a portfolio and existing suborganization
+        portfolio = Portfolio.objects.create(
+            organization_name="Test Portfolio",
+            creator=self.superuser
+        )
+        
+        # Create an existing suborganization
+        Suborganization.objects.create(
+            name="Existing Suborg",
+            portfolio=portfolio
+        )
+        
+        # Create a domain request trying to use the same suborganization name
+        # (intentionally lowercase)
+        domain_request = completed_domain_request(
+            name="test1234.gov",
+            portfolio=portfolio,
+            requested_suborganization="existing suborg",
+            suborganization_city="Rome",
+            suborganization_state_territory=DomainRequest.StateTerritoryChoices.OHIO,
+        )
+
+        # Assert that the validation error is raised
+        with self.assertRaises(ValidationError) as err:
+            domain_request.clean()
+        
+        self.assertIn(
+            "This suborganization already exists",
+            str(err.exception)
+        )
+
+        # Test that a different name is allowed. Should not raise a error.
+        domain_request.requested_suborganization = "New Suborg"
+        domain_request.clean()
+
+    @less_console_noise_decorator
+    @override_flag("organization_feature", active=True)
+    def test_clean_validates_partial_suborganization_fields(self):
+        """Tests that clean() enforces all-or-nothing rule for suborganization fields"""
+        portfolio = Portfolio.objects.create(
+            organization_name="Test Portfolio",
+            creator=self.superuser
+        )
+        
+        # Create domain request with only city filled out
+        domain_request = completed_domain_request(
+            name="test1234.gov",
+            portfolio=portfolio,
+            suborganization_city="Test City",
+        )
+
+        # Assert validation error is raised with correct missing fields
+        with self.assertRaises(ValidationError) as err:
+            domain_request.clean()
+        
+        error_dict = err.exception.error_dict
+        expected_missing = ["requested_suborganization", "suborganization_state_territory"]
+        
+        # Verify correct fields are flagged as required
+        self.assertEqual(
+            sorted(error_dict.keys()),
+            sorted(expected_missing)
+        )
+        
+        # Verify error message
+        for field in expected_missing:
+            self.assertEqual(
+                str(error_dict[field][0].message),
+                "This field is required when creating a new suborganization."
+            )
+
+        # When all data is passed in, this should validate correctly
+        domain_request.requested_suborganization = "Complete Suborg"
+        domain_request.suborganization_state_territory = DomainRequest.StateTerritoryChoices.OHIO
+        # Assert that no ValidationError is raised
+        try:
+            domain_request.clean()
+        except ValidationError as e:
+            self.fail(f"ValidationError was raised unexpectedly: {e}")
+        
+        # Also ensure that no validation error is raised if nothing is passed in at all
+        domain_request.suborganization_city = None
+        domain_request.requested_suborganization = None
+        domain_request.suborganization_state_territory = None
+        try:
+            domain_request.clean()
+        except ValidationError as e:
+            self.fail(f"ValidationError was raised unexpectedly: {e}")
+
     @less_console_noise_decorator
     def test_domain_request_senior_official_is_alphabetically_sorted(self):
         """Tests if the senior offical dropdown is alphanetically sorted in the django admin display"""