diff --git a/app/broadcast_areas/utils.py b/app/broadcast_areas/utils.py
index cd4ec378d..48766073d 100644
--- a/app/broadcast_areas/utils.py
+++ b/app/broadcast_areas/utils.py
@@ -7,7 +7,7 @@ def aggregate_areas(areas):
     areas = _convert_custom_areas_to_wards(areas)
     areas = _aggregate_wards_by_local_authority(areas)
     areas = _aggregate_lower_tier_authorities(areas)
-    return areas
+    return sorted(areas)
 
 
 def _convert_custom_areas_to_wards(areas):
diff --git a/app/models/broadcast_message.py b/app/models/broadcast_message.py
index 8b9878a8c..5e1a5deb4 100644
--- a/app/models/broadcast_message.py
+++ b/app/models/broadcast_message.py
@@ -11,6 +11,7 @@ from app.broadcast_areas.models import (
     CustomBroadcastAreas,
     broadcast_area_libraries,
 )
+from app.broadcast_areas.utils import aggregate_areas
 from app.formatters import round_to_significant_figures
 from app.models import JSONModel, ModelList
 from app.models.user import User
@@ -244,6 +245,7 @@ class BroadcastMessage(JSONModel):
         areas = {
             'ids': self.area_ids,
             'names': [area.name for area in self.areas],
+            'aggregate_names': [area.name for area in aggregate_areas(self.areas)],
             'simple_polygons': self.simple_polygons.as_coordinate_pairs_lat_long
         }
 
diff --git a/tests/app/broadcast_areas/test_utils.py b/tests/app/broadcast_areas/test_utils.py
index c95b75eff..8ed121995 100644
--- a/tests/app/broadcast_areas/test_utils.py
+++ b/tests/app/broadcast_areas/test_utils.py
@@ -99,9 +99,9 @@ def test_aggregate_areas(
         broadcast_message_json(area_ids=area_ids)
     )
 
-    assert sorted(
+    assert [
         area.name for area in aggregate_areas(broadcast_message.areas)
-    ) == expected_area_names
+    ] == expected_area_names
 
 
 @pytest.mark.parametrize(('simple_polygons', 'expected_area_names'), [
@@ -180,6 +180,6 @@ def test_aggregate_areas_for_custom_polygons(
         )
     )
 
-    assert sorted(
+    assert [
         area.name for area in aggregate_areas(broadcast_message.areas)
-    ) == expected_area_names
+    ] == expected_area_names
diff --git a/tests/app/main/views/test_broadcast.py b/tests/app/main/views/test_broadcast.py
index 414b1502c..e50b0a858 100644
--- a/tests/app/main/views/test_broadcast.py
+++ b/tests/app/main/views/test_broadcast.py
@@ -1398,6 +1398,7 @@ def test_add_broadcast_area(
             'areas': {
                 'ids': ['ctry19-E92000001', 'ctry19-S92000003', 'ctry19-W92000004'],
                 'names': ['England', 'Scotland', 'Wales'],
+                'aggregate_names': ['England', 'Scotland', 'Wales'],
                 'simple_polygons': coordinates
             }
         },
@@ -1411,7 +1412,9 @@ def test_add_broadcast_area(
         },
         {
             # wd20-S13002845 is ignored because the user chose ‘Select all…’
-            'ids': ['lad20-S12000033'], 'names': ['Aberdeen City']
+            'ids': ['lad20-S12000033'],
+            'names': ['Aberdeen City'],
+            'aggregate_names': ['Aberdeen City']
         }
     ),
     (
@@ -1421,6 +1424,7 @@ def test_add_broadcast_area(
         {
             'ids': ['wd20-S13002845', 'wd20-S13002836'],
             'names': ['Bridge of Don', 'Airyhall/Broomhill/Garthdee'],
+            'aggregate_names': ['Aberdeen City'],
         }
     ),
 ))
@@ -1454,6 +1458,7 @@ def test_add_broadcast_sub_area_district_view(
     # These two areas are on the broadcast already
     expected_data['ids'] = ['ctry19-E92000001', 'ctry19-S92000003'] + expected_data['ids']
     expected_data['names'] = ['England', 'Scotland'] + expected_data['names']
+    expected_data['aggregate_names'] = sorted(['England', 'Scotland'] + expected_data['aggregate_names'])
 
     mock_update_broadcast_message.assert_called_once_with(
         service_id=SERVICE_ONE_ID,
@@ -1504,7 +1509,8 @@ def test_add_broadcast_sub_area_county_view(
                 ] + [
                     'ctyua19-E10000016'
                 ],
-                'names': ['England', 'Scotland', 'Kent']
+                'names': ['England', 'Scotland', 'Kent'],
+                'aggregate_names': ['England', 'Kent', 'Scotland']
             }
         },
     )
@@ -1545,6 +1551,7 @@ def test_remove_broadcast_area_page(
             'areas': {
                 'simple_polygons': coordinates,
                 'names': ['Scotland'],
+                'aggregate_names': ['Scotland'],
                 'ids': ['ctry19-S92000003']
             },
         },