diff --git a/backend/pashub_fetcher/tests/test_pashub_service.py b/backend/pashub_fetcher/tests/test_pashub_service.py
index ff4a8977..991d2a46 100644
--- a/backend/pashub_fetcher/tests/test_pashub_service.py
+++ b/backend/pashub_fetcher/tests/test_pashub_service.py
@@ -291,6 +291,21 @@ def test_run_raises_unauthorized_when_pas_401_and_no_factory() -> None:
         service.run(make_request())
 
 
+def test_run_raises_unauthorized_when_both_clients_401() -> None:
+    pas_client = MagicMock(spec=PashubClient)
+    pas_client.get_uprn_by_job_id.side_effect = UnauthorizedError()
+
+    coord_client = MagicMock(spec=PashubClient)
+    coord_client.get_uprn_by_job_id.side_effect = UnauthorizedError()
+
+    factory = MagicMock(return_value=coord_client)
+
+    service = make_service(pashub_client=pas_client, coordination_client_factory=factory)
+
+    with pytest.raises(UnauthorizedError):
+        service.run(make_request())
+
+
 def test_run_warns_and_continues_when_site_notes_parsing_fails() -> None:
     mock_client = MagicMock(spec=PashubClient)
     mock_client.get_uprn_by_job_id.return_value = None