diff --git a/app/broadcast_message/broadcast_message_schema.py b/app/broadcast_message/broadcast_message_schema.py
index 743ca54d7..3d617533a 100644
--- a/app/broadcast_message/broadcast_message_schema.py
+++ b/app/broadcast_message/broadcast_message_schema.py
@@ -14,6 +14,7 @@ create_broadcast_message_schema = {
         'starts_at': {'type': 'string', 'format': 'datetime'},
         'finishes_at': {'type': 'string', 'format': 'datetime'},
         'areas': {"type": "array", "items": {"type": "string"}},
+        'simple_polygons': {"type": "array", "items": {"type": "array"}},
     },
     'required': ['template_id', 'service_id', 'created_by'],
     'additionalProperties': False
@@ -29,6 +30,7 @@ update_broadcast_message_schema = {
         'starts_at': {'type': 'string', 'format': 'datetime'},
         'finishes_at': {'type': 'string', 'format': 'datetime'},
         'areas': {"type": "array", "items": {"type": "string"}},
+        'simple_polygons': {"type": "array", "items": {"type": "array"}},
     },
     'required': [],
     'additionalProperties': False
diff --git a/app/broadcast_message/rest.py b/app/broadcast_message/rest.py
index db7f459c8..1438b29f9 100644
--- a/app/broadcast_message/rest.py
+++ b/app/broadcast_message/rest.py
@@ -101,7 +101,7 @@ def create_broadcast_message(service_id):
         template_id=template.id,
         template_version=template.version,
         personalisation=data.get('personalisation', {}),
-        areas=data.get('areas', []),
+        areas=data.get('areas', {}),
         status=BroadcastStatusType.DRAFT,
         starts_at=_parse_nullable_datetime(data.get('starts_at')),
         finishes_at=_parse_nullable_datetime(data.get('finishes_at')),
@@ -133,8 +133,8 @@ def update_broadcast_message(service_id, broadcast_message_id):
         broadcast_message.starts_at = _parse_nullable_datetime(data['starts_at'])
     if 'finishes_at' in data:
         broadcast_message.finishes_at = _parse_nullable_datetime(data['finishes_at'])
-    if 'areas' in data:
-        broadcast_message.areas = data['areas']
+    if 'areas' in data and 'simple_polygons' in data:
+        broadcast_message.areas = {"areas": data["areas"], "simple_polygons": data["simple_polygons"]}
 
     dao_save_object(broadcast_message)
 
diff --git a/app/models.py b/app/models.py
index 72e900af4..cde9874a7 100644
--- a/app/models.py
+++ b/app/models.py
@@ -2263,7 +2263,7 @@ class BroadcastMessage(db.Model):
             'template_name': self.template.name,
 
             'personalisation': self.personalisation,
-            'areas': self.areas,
+            'areas': self.areas.get("areas", []),
 
             'status': self.status,
 
diff --git a/tests/app/broadcast_message/test_rest.py b/tests/app/broadcast_message/test_rest.py
index d9c04cc9d..2a17451b2 100644
--- a/tests/app/broadcast_message/test_rest.py
+++ b/tests/app/broadcast_message/test_rest.py
@@ -11,7 +11,10 @@ from tests.app.db import create_broadcast_message, create_template, create_servi
 
 def test_get_broadcast_message(admin_request, sample_service):
     t = create_template(sample_service, BROADCAST_TYPE)
-    bm = create_broadcast_message(t, areas=['place A', 'region B'])
+    bm = create_broadcast_message(t, areas={
+        "areas": ['place A', 'region B'],
+        "simple_polygons": [[50.1, 1.2], [50.12, 1.2]]
+    })
 
     response = admin_request.get(
         'broadcast_message.get_broadcast_message',
@@ -177,7 +180,10 @@ def test_update_broadcast_message_doesnt_allow_edits_after_broadcast_goes_live(a
 
 def test_update_broadcast_message_sets_finishes_at_separately(admin_request, sample_service):
     t = create_template(sample_service, BROADCAST_TYPE)
-    bm = create_broadcast_message(t, areas=['manchester'])
+    bm = create_broadcast_message(
+        t,
+        areas={"areas": ['london'], "simple_polygons": [[50.12, 1.2], [50.13, 1.2], [50.14, 1.21]]}
+    )
 
     response = admin_request.post(
         'broadcast_message.update_broadcast_message',
diff --git a/tests/app/celery/test_broadcast_message_tasks.py b/tests/app/celery/test_broadcast_message_tasks.py
index b39744e2f..e6c82c35a 100644
--- a/tests/app/celery/test_broadcast_message_tasks.py
+++ b/tests/app/celery/test_broadcast_message_tasks.py
@@ -11,7 +11,11 @@ from tests.app.db import create_template, create_broadcast_message, create_broad
 
 def test_send_broadcast_message_sends_data_correctly(sample_service):
     template = create_template(sample_service, BROADCAST_TYPE)
-    broadcast_message = create_broadcast_message(template, areas=['london'], status=BroadcastStatusType.BROADCASTING)
+    broadcast_message = create_broadcast_message(
+        template,
+        areas={"areas": ['london'], "simple_polygons": [[50.12, 1.2], [50.13, 1.2], [50.14, 1.21]]},
+        status=BroadcastStatusType.BROADCASTING
+    )
 
     with requests_mock.Mocker() as request_mock:
         request_mock.post("http://test-cbc-proxy/broadcasts/stub-1", json={'valid': 'true'}, status_code=200)
@@ -29,7 +33,11 @@ def test_send_broadcast_message_sends_data_correctly(sample_service):
 
 def test_send_broadcast_message_sends_old_version_of_template(sample_service):
     template = create_template(sample_service, BROADCAST_TYPE, content='first content')
-    broadcast_message = create_broadcast_message(template, areas=['london'], status=BroadcastStatusType.BROADCASTING)
+    broadcast_message = create_broadcast_message(
+        template,
+        areas={"areas": ['london'], "simple_polygons": [[50.12, 1.2], [50.13, 1.2], [50.14, 1.21]]},
+        status=BroadcastStatusType.BROADCASTING
+    )
 
     template.content = 'second content'
     dao_update_template(template)
diff --git a/tests/app/db.py b/tests/app/db.py
index 75d4edeaa..89e42ec15 100644
--- a/tests/app/db.py
+++ b/tests/app/db.py
@@ -1006,7 +1006,7 @@ def create_broadcast_message(
     status=BroadcastStatusType.DRAFT,
     starts_at=None,
     finishes_at=None,
-    areas=[],
+    areas={},
 ):
     broadcast_message = BroadcastMessage(
         service_id=template.service_id,