diff --git a/app/broadcast_message/rest.py b/app/broadcast_message/rest.py
index 112963907..9a50c5cfe 100644
--- a/app/broadcast_message/rest.py
+++ b/app/broadcast_message/rest.py
@@ -157,11 +157,14 @@ def create_broadcast_message(service_id):
 def update_broadcast_message(service_id, broadcast_message_id):
     data = request.get_json()
 
+    # TEMPORARY: while we migrate and backfill "areas"
+    force_override = data.pop("force_override", False)
+
     validate(data, update_broadcast_message_schema)
 
     broadcast_message = dao_get_broadcast_message_by_id_and_service_id(broadcast_message_id, service_id)
 
-    if broadcast_message.status not in BroadcastStatusType.PRE_BROADCAST_STATUSES:
+    if not force_override and broadcast_message.status not in BroadcastStatusType.PRE_BROADCAST_STATUSES:
         raise InvalidRequest(
             f'Cannot update broadcast_message {broadcast_message.id} while it has status {broadcast_message.status}',
             status_code=400
diff --git a/tests/app/broadcast_message/test_rest.py b/tests/app/broadcast_message/test_rest.py
index 492d808a0..5c94fd6e1 100644
--- a/tests/app/broadcast_message/test_rest.py
+++ b/tests/app/broadcast_message/test_rest.py
@@ -385,6 +385,10 @@ def test_update_broadcast_message_allows_edit_while_not_yet_live(admin_request,
     assert response['updated_at'] is not None
 
 
+@pytest.mark.parametrize('force_override', [
+    False,
+    pytest.param(True, marks=pytest.mark.xfail)
+])
 @pytest.mark.parametrize('status', [
     BroadcastStatusType.BROADCASTING,
     BroadcastStatusType.CANCELLED,
@@ -392,14 +396,17 @@ def test_update_broadcast_message_allows_edit_while_not_yet_live(admin_request,
     BroadcastStatusType.TECHNICAL_FAILURE,
 ])
 def test_update_broadcast_message_doesnt_allow_edits_after_broadcast_goes_live(
-    admin_request, sample_broadcast_service, status
+    admin_request,
+    force_override,
+    sample_broadcast_service,
+    status
 ):
     t = create_template(sample_broadcast_service, BROADCAST_TYPE)
     bm = create_broadcast_message(t, areas=['manchester'], status=status)
 
     response = admin_request.post(
         'broadcast_message.update_broadcast_message',
-        _data={'areas': ['london', 'glasgow']},
+        _data={'areas': ['london', 'glasgow'], 'force_override': force_override},
         service_id=t.service_id,
         broadcast_message_id=bm.id,
         _expected_status=400