diff --git a/app/broadcast_areas/models.py b/app/broadcast_areas/models.py
index b33ee1ee4..d7776c4ed 100644
--- a/app/broadcast_areas/models.py
+++ b/app/broadcast_areas/models.py
@@ -124,23 +124,21 @@ class BroadcastArea(BaseBroadcastArea, SortableMixin):
         return self._count_of_phones or 0
 
     @cached_property
-    def parents(self):
-        return list(filter(None, self._parents_iterator))
+    def ancestors(self):
+        return list(self._ancestors_iterator)
 
     @property
-    def _parents_iterator(self):
+    def _ancestors_iterator(self):
         id = self.id
 
         while True:
             parent = BroadcastAreasRepository().get_parent_for_area(id)
 
             if not parent:
-                return None
+                return
 
             parent_broadcast_area = BroadcastArea(parent)
-
             yield parent_broadcast_area
-
             id = parent_broadcast_area.id
 
 
@@ -165,10 +163,11 @@ class CustomBroadcastArea(BaseBroadcastArea):
     simple_polygons = polygons
 
     @cached_property
-    def overlapping_areas(self):
+    def nearby_electoral_wards(self):
         if not self.polygons:
             return []
         return broadcast_area_libraries.get_areas_with_simple_polygons([
+            # We only index electoral wards in the RTree
             overlap.data for overlap in rtree_index.query(
                 Rect(*self.polygons.bounds)
             )
@@ -178,7 +177,7 @@ class CustomBroadcastArea(BaseBroadcastArea):
     def count_of_phones(self):
         return sum(
             area.simple_polygons.ratio_of_intersection_with(self.polygons) * area.count_of_phones
-            for area in self.overlapping_areas
+            for area in self.nearby_electoral_wards
         )
 
 
diff --git a/app/models/broadcast_message.py b/app/models/broadcast_message.py
index 14c4c9525..112e234f7 100644
--- a/app/models/broadcast_message.py
+++ b/app/models/broadcast_message.py
@@ -104,14 +104,14 @@ class BroadcastMessage(JSONModel):
         )
 
     @property
-    def parent_areas(self):
-        return sorted(set(self._parent_areas_iterator))
+    def ancestor_areas(self):
+        return sorted(set(self._ancestor_areas_iterator))
 
     @property
-    def _parent_areas_iterator(self):
+    def _ancestor_areas_iterator(self):
         for area in self.areas:
-            for parent in area.parents:
-                yield parent
+            for ancestor in area.ancestors:
+                yield ancestor
 
     @cached_property
     def polygons(self):
diff --git a/app/templates/views/broadcast/libraries.html b/app/templates/views/broadcast/libraries.html
index 502d1d35f..a90b80011 100644
--- a/app/templates/views/broadcast/libraries.html
+++ b/app/templates/views/broadcast/libraries.html
@@ -14,7 +14,7 @@
 
   {{ page_header("Choose where to send this alert") }}
 
-  {% for area in broadcast_message.parent_areas %}
+  {% for area in broadcast_message.ancestor_areas %}
     <a class="govuk-heading-m govuk-link govuk-link--no-visited-state" href="{{ url_for('.choose_broadcast_sub_area', service_id=current_service.id, broadcast_message_id=broadcast_message.id, library_slug=area.library_id, area_slug=area.id) }}">{{ area.name }}</a>
     {% if loop.last %}
       <div class="keyline-block"></div>
diff --git a/requirements.in b/requirements.in
index b828b23ab..ca9d5f69f 100644
--- a/requirements.in
+++ b/requirements.in
@@ -26,7 +26,7 @@ fido2==0.9.1
 awscli-cwlogs>=1.4,<1.5
 itsdangerous==1.1.0  # pyup: <2
 
-git+https://github.com/alphagov/notifications-utils.git@44.4.3#egg=notifications-utils==44.4.3
+git+https://github.com/alphagov/notifications-utils.git@44.5.0#egg=notifications-utils==44.5.0
 git+https://github.com/alphagov/govuk-frontend-jinja.git@v0.5.8-alpha#egg=govuk-frontend-jinja==0.5.8-alpha
 
 # cryptography 3.4+ incorporates Rust code, which isn't supported on PaaS
diff --git a/requirements.txt b/requirements.txt
index 4abcbfda2..9d37aad32 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -118,7 +118,7 @@ mistune==0.8.4
     # via notifications-utils
 notifications-python-client==6.2.1
     # via -r requirements.in
-git+https://github.com/alphagov/notifications-utils.git@44.4.3#egg=notifications-utils==44.4.3
+git+https://github.com/alphagov/notifications-utils.git@44.5.0#egg=notifications-utils==44.5.0
     # via -r requirements.in
 openpyxl==3.0.7
     # via pyexcel-xlsx
diff --git a/tests/app/broadcast_areas/test_broadcast_area.py b/tests/app/broadcast_areas/test_broadcast_area.py
index 4c2af384b..ef862f10d 100644
--- a/tests/app/broadcast_areas/test_broadcast_area.py
+++ b/tests/app/broadcast_areas/test_broadcast_area.py
@@ -386,7 +386,7 @@ def test_count_of_phones_for_custom_area(
     )
 
     assert sorted(
-        overlap.name for overlap in area.overlapping_areas
+        overlap.name for overlap in area.nearby_electoral_wards
     ) == expected_possible_overlaps
 
     assert close_enough(area.count_of_phones, expected_count_of_phones)