diff --git a/src/blueapi/utils/numtracker.py b/src/blueapi/utils/numtracker.py
index 91e3c66c2a..ddd489f877 100644
--- a/src/blueapi/utils/numtracker.py
+++ b/src/blueapi/utils/numtracker.py
@@ -105,6 +105,14 @@ async def create_scan(
         json = response.json()
 
         if json.get("errors") is not None:
+            for error in json["errors"]:
+                code = (error.get("extensions") or {}).get("code")
+
+                if code == "AUTH_FAILED":
+                    raise RuntimeError(
+                        f"Not authorised to create a scan number for "
+                        f"{instrument} and {instrument_session}."
+                    )
             raise RuntimeError(f"Numtracker error: {json['errors']}")
 
         new_collection = NumtrackerScanMutationResponse.model_validate(json["data"])
diff --git a/tests/unit_tests/utils/test_numtracker.py b/tests/unit_tests/utils/test_numtracker.py
index 859dbaf098..c69ff0b01d 100644
--- a/tests/unit_tests/utils/test_numtracker.py
+++ b/tests/unit_tests/utils/test_numtracker.py
@@ -33,6 +33,18 @@ def numtracker() -> NumtrackerClient:
     ],
 }
 
+AUTH_ERROR = {
+    "data": None,
+    "errors": [
+        {
+            "message": "No configuration available for instrument p46",
+            "locations": [{"line": 3, "column": 5}],
+            "path": ["scan"],
+            "extensions": {"code": "AUTH_FAILED"},
+        }
+    ],
+}
+
 
 async def test_create_scan(
     numtracker: NumtrackerClient, httpx_mock: HTTPXMock, nt_query, nt_response
@@ -109,3 +121,19 @@ async def test_create_scan_raises_runtime_error_on_graphql_error(
     )
     with pytest.raises(RuntimeError, match="Numtracker error:"):
         await numtracker.create_scan("ab123", "p46")
+
+
+async def test_create_scan_raises_runtime_auth_error_on_graphql_error(
+    numtracker: NumtrackerClient, httpx_mock: HTTPXMock, nt_query
+):
+    httpx_mock.add_response(
+        method="POST",
+        url=URL,
+        match_json=nt_query,
+        status_code=200,
+        json=AUTH_ERROR,
+    )
+    with pytest.raises(
+        RuntimeError, match="Not authorised to create a scan number for p46 and ab123"
+    ):
+        await numtracker.create_scan("ab123", "p46")