diff --git a/api/permissions/permission_service.py b/api/permissions/permission_service.py
index 07b25b4124c4..6a0a28e263b3 100644
--- a/api/permissions/permission_service.py
+++ b/api/permissions/permission_service.py
@@ -1,3 +1,4 @@
+import typing
 from typing import TYPE_CHECKING, List, Set, Union
 
 from django.conf import settings
@@ -202,23 +203,33 @@ def user_has_organisation_permission(
     if is_user_organisation_admin(user, organisation):
         return True
 
-    # NOTE: since we store organisation admin slightly differently
-    # compared to project and environment `get_base_permission_filter`
-    # with allow_admin=True will not work for organisation
-    base_filter = get_base_permission_filter(
-        user,
-        Organisation,  # type: ignore[arg-type]
-        permission_key,
-        allow_admin=False,
-    )
-    filter_ = base_filter & Q(id=organisation.id)
+    # Base query to ensure the user actually belongs to the organisation
+    base_qs = Organisation.objects.filter(id=organisation.id, users=user)
 
-    queryset = Organisation.objects.filter(filter_)
+    # 1. Check direct user permissions (Fastest)
+    user_filter = get_user_permission_filter(user, permission_key, allow_admin=False)
+    if base_qs.filter(user_filter).exists():
+        return True
 
-    # Final check to verify that user belongs to organisation
-    queryset = queryset.filter(users=user)
+    # 2. Check group permissions
+    group_filter = get_group_permission_filter(user, permission_key, allow_admin=False)
+    if base_qs.filter(group_filter).exists():
+        return True
 
-    return queryset.exists()  # type: ignore[no-any-return]
+    # 3. Check role permissions (only if RBAC is installed)
+    if settings.IS_RBAC_INSTALLED:  # pragma: no cover
+        role_filter = get_role_permission_filter(
+            user,
+            # Type gap: get_role_permission_filter type hint expects an instance,
+            # but safely handles the model class at runtime.
+            typing.cast(typing.Any, Organisation),
+            permission_key,
+            allow_admin=False,
+        )
+        if base_qs.filter(role_filter).exists():
+            return True
+
+    return False
 
 
 def master_api_key_has_organisation_permission(
diff --git a/api/tests/unit/permissions/permission_service/test_user_has_organisation_permissions.py b/api/tests/unit/permissions/permission_service/test_user_has_organisation_permissions.py
index 1798892cc473..84f883e2660c 100644
--- a/api/tests/unit/permissions/permission_service/test_user_has_organisation_permissions.py
+++ b/api/tests/unit/permissions/permission_service/test_user_has_organisation_permissions.py
@@ -1,3 +1,5 @@
+import typing
+
 from organisations.models import Organisation, UserOrganisation
 from organisations.permissions.models import (
     OrganisationPermissionModel,
@@ -156,3 +158,34 @@ def test_user_has_organisation_permission__user_removed_from_organisation__retur
         organisation=organisation,
         permission_key=CREATE_PROJECT,
     )
+
+
+def test_user_has_organisation_permission__evaluating_permission__executes_exact_queries(
+    django_assert_num_queries: typing.Any,
+    django_user_model: typing.Any,
+    organisation: typing.Any,
+) -> None:
+    # Given
+    user = django_user_model.objects.create(email="test_sequential_eval@example.com")
+    user.add_organisation(organisation)
+
+    # When
+    with django_assert_num_queries(3) as ctx:
+        has_permission = user_has_organisation_permission(
+            user=user, organisation=organisation, permission_key="MANAGE_USER_GROUPS"
+        )
+
+    # Then
+    assert has_permission is False
+
+    # Verify the exact queries executed match the expected sequential EXISTS pattern
+    queries = [query["sql"].lower() for query in ctx.captured_queries]
+
+    # Query 1: Base user organisation role check
+    assert "organisations_userorganisation" in queries[0]
+
+    # Query 2: User-specific permission check
+    assert "organisation_permissions_userorganisationpermission" in queries[1]
+
+    # Query 3: Group-specific permission check
+    assert "organisation_permissions_userpermissiongroup" in queries[2]
diff --git a/api/tests/unit/users/test_unit_users_models.py b/api/tests/unit/users/test_unit_users_models.py
index 475a28af9647..e95e622d62dc 100644
--- a/api/tests/unit/users/test_unit_users_models.py
+++ b/api/tests/unit/users/test_unit_users_models.py
@@ -9,7 +9,10 @@
 from organisations.permissions.permissions import ORGANISATION_PERMISSIONS
 from projects.models import Project
 from tests.types import WithProjectPermissionsCallable
-from users.models import FFAdminUser, UserPermissionGroup
+from users.models import (
+    FFAdminUser,
+    UserPermissionGroup,
+)
 
 
 def test_belongs_to__user_in_organisation__returns_true(