diff --git a/app/v2/broadcast/post_broadcast.py b/app/v2/broadcast/post_broadcast.py
index 4bff51e4c..7f1259040 100644
--- a/app/v2/broadcast/post_broadcast.py
+++ b/app/v2/broadcast/post_broadcast.py
@@ -5,9 +5,13 @@ from notifications_utils.polygons import Polygons
 from notifications_utils.template import BroadcastMessageTemplate
 
 from app import api_user, authenticated_service
-from app.broadcast_message.rest import validate_and_update_broadcast_message_status
+from app.broadcast_message.rest import (
+    validate_and_update_broadcast_message_status,
+)
 from app.broadcast_message.translators import cap_xml_to_dict
-from app.dao.broadcast_message_dao import dao_get_broadcast_message_by_references
+from app.dao.broadcast_message_dao import (
+    dao_get_broadcast_message_by_references,
+)
 from app.dao.dao_utils import dao_save_object
 from app.models import BROADCAST_TYPE, BroadcastMessage, BroadcastStatusType
 from app.notifications.validators import check_service_has_permission
@@ -47,9 +51,13 @@ def create_broadcast():
         references_to_original_broadcast = broadcast_json["references"].split(",")
         broadcast_message = dao_get_broadcast_message_by_references(references_to_original_broadcast)
         # do we need to check if service is active?
+        if broadcast_message.status == BroadcastStatusType.PENDING_APPROVAL:
+            new_status = BroadcastStatusType.REJECTED
+        else:
+            new_status = BroadcastStatusType.CANCELLED
         validate_and_update_broadcast_message_status(
             broadcast_message,
-            BroadcastStatusType.REJECTED,
+            new_status,
             updating_user=None,
             from_api=True
         )
diff --git a/tests/app/v2/broadcast/test_post_broadcast.py b/tests/app/v2/broadcast/test_post_broadcast.py
index eb8f5e4ad..c33ceec61 100644
--- a/tests/app/v2/broadcast/test_post_broadcast.py
+++ b/tests/app/v2/broadcast/test_post_broadcast.py
@@ -155,8 +155,54 @@ def test_valid_cancel_broadcast_request_rejects_unapproved_alert_and_returns_201
     assert response_json_for_reject['updated_at'] is not None
 
 
-def test_valid_cancel_broadcast_request_cancels_active_alert_and_returns_201():
-    pass
+def test_valid_cancel_broadcast_request_cancels_active_alert_and_returns_201(
+    client,
+    sample_broadcast_service,
+    notify_db,
+    notify_db_session,
+    mocker
+):
+    auth_header = create_service_authorization_header(service_id=sample_broadcast_service.id)
+
+    # create a broadcast
+    response_for_create = client.post(
+        path='/v2/broadcast',
+        data=sample_cap_xml_documents.WAINFLEET,
+        headers=[('Content-Type', 'application/cap+xml'), auth_header],
+    )
+    assert response_for_create.status_code == 201
+
+    response_json_for_create = json.loads(response_for_create.get_data(as_text=True))
+
+    assert response_json_for_create['cancelled_at'] is None
+    assert response_json_for_create['cancelled_by_id'] is None
+    assert response_json_for_create['reference'] == '50385fcb0ab7aa447bbd46d848ce8466E'
+    assert response_json_for_create['status'] == 'pending-approval'
+
+    # approve broadcast
+    broadcast_message = dao_get_broadcast_message_by_id_and_service_id(
+        response_json_for_create["id"], response_json_for_create["service_id"]
+    )
+    broadcast_message.status = 'broadcasting'
+
+    # cancel broadcast
+    mock_task = mocker.patch('app.celery.broadcast_message_tasks.send_broadcast_event.apply_async')
+
+    response_for_cancel = client.post(
+        path='/v2/broadcast',
+        data=sample_cap_xml_documents.WAINFLEET_CANCEL,
+        headers=[('Content-Type', 'application/cap+xml'), auth_header],
+    )
+    assert response_for_cancel.status_code == 201
+
+    assert len(broadcast_message.events) == 1
+    alert_event = broadcast_message.events[0]
+    mock_task.assert_called_once_with(kwargs={'broadcast_event_id': str(alert_event.id)}, queue='broadcast-tasks')
+
+    assert broadcast_message.status == 'cancelled'
+    assert broadcast_message.cancelled_at is not None
+    assert broadcast_message.cancelled_by_id is None  # broadcast cancelled via API, so not by any single user
+    assert broadcast_message.updated_at is not None
 
 
 def test_cancel_request_does_not_cancel_broadcast_if_reference_does_not_match():