diff --git a/infrastructure/hubspot/deal_properties_client.py b/infrastructure/hubspot/deal_properties_client.py
index f97a51448..cf6966fb1 100644
--- a/infrastructure/hubspot/deal_properties_client.py
+++ b/infrastructure/hubspot/deal_properties_client.py
@@ -1,7 +1,8 @@
-from typing import Any, Dict, Optional, cast
+from typing import Dict, Optional, cast
 
 from hubspot.client import Client  # type: ignore[reportMissingTypeStubs]
 from hubspot.crm.deals import SimplePublicObjectInput  # type: ignore[reportMissingTypeStubs]
+from hubspot.crm.objects.models import SimplePublicObject as HubspotObject  # type: ignore[reportMissingTypeStubs]
 
 from infrastructure.hubspot.scrubbed_calls import scrubbed_call_with_retry
 
@@ -24,12 +25,17 @@ class HubspotDealPropertiesClient:
         a property whole (HubSpot has no append) would otherwise overwrite
         edits made since the last scrape.
         """
-        deal: Any = scrubbed_call_with_retry(
-            lambda: self._client.crm.deals.basic_api.get_by_id(  # type: ignore[reportUnknownMemberType]
-                deal_id, properties=[property_name]
+        deal: HubspotObject = scrubbed_call_with_retry(
+            lambda: cast(
+                HubspotObject,
+                self._client.crm.deals.basic_api.get_by_id(  # type: ignore[reportUnknownMemberType]
+                    deal_id, properties=[property_name]
+                ),
             )
         )
-        properties = cast(Dict[str, Optional[str]], deal.properties)
+        properties: Dict[str, Optional[str]] = cast(
+            Dict[str, Optional[str]], deal.properties  # type: ignore[reportUnknownMemberType]
+        )
         return properties.get(property_name)
 
     def write_deal_property(
diff --git a/tests/orchestration/test_abri_orchestrator_tenant_data_sync.py b/tests/orchestration/test_abri_orchestrator_tenant_data_sync.py
index a62580bd4..f0b8c8aed 100644
--- a/tests/orchestration/test_abri_orchestrator_tenant_data_sync.py
+++ b/tests/orchestration/test_abri_orchestrator_tenant_data_sync.py
@@ -10,10 +10,12 @@ import requests
 from hubspot.crm.associations.v4 import AssociationSpec  # type: ignore[reportMissingTypeStubs]
 from hubspot.crm.contacts import ApiException as ContactsApiException  # type: ignore[reportMissingTypeStubs]
 from hubspot.crm.contacts import SimplePublicObjectInputForCreate  # type: ignore[reportMissingTypeStubs]
+from hubspot.crm.deals import ApiException as DealsApiException  # type: ignore[reportMissingTypeStubs]
 from hubspot.crm.deals import SimplePublicObjectInput as DealPropertyInput  # type: ignore[reportMissingTypeStubs]
 
 from domain.abri.models import AbriRequestRejected, PlaceRef
 from infrastructure.hubspot.deal_contacts_client import HubspotDealContactsClient
+from infrastructure.hubspot.errors import HubspotRequestError
 from infrastructure.hubspot.deal_properties_client import HubspotDealPropertiesClient
 from infrastructure.abri.abri_client import AbriClient
 from infrastructure.abri.config import AbriConfig
@@ -588,3 +590,72 @@ def test_a_void_property_is_flagged_at_the_front_of_the_deals_booking_informatio
             properties={"notes_for_surveyor": "Void || Key safe code 1234"}
         ),
     )
+
+
+def test_a_void_property_with_no_existing_booking_information_is_flagged_alone(
+    orchestrator: AbriOrchestrator,
+    mock_session: MagicMock,
+    sdk_client: MagicMock,
+) -> None:
+    # Arrange: HubSpot sends "" for an unset property.
+    mock_session.post.return_value.content = _load_fixture(
+        "abri_relay_getscstenantdata_notenancyfound_response.xml"
+    )
+    sdk_client.crm.deals.basic_api.get_by_id.return_value.properties = {
+        "notes_for_surveyor": ""
+    }
+
+    # Act
+    orchestrator.sync_tenant_data(PLACE_REF, deal_id=DEAL_ID)
+
+    # Assert: no dangling separator on an otherwise empty note.
+    sdk_client.crm.deals.basic_api.update.assert_called_once_with(
+        DEAL_ID,
+        simple_public_object_input=DealPropertyInput(
+            properties={"notes_for_surveyor": "Void ||"}
+        ),
+    )
+
+
+def test_a_deal_already_flagged_void_is_left_alone_so_redelivery_never_stacks_flags(
+    orchestrator: AbriOrchestrator,
+    mock_session: MagicMock,
+    sdk_client: MagicMock,
+) -> None:
+    # Arrange: the state a redelivered message finds.
+    mock_session.post.return_value.content = _load_fixture(
+        "abri_relay_getscstenantdata_notenancyfound_response.xml"
+    )
+    sdk_client.crm.deals.basic_api.get_by_id.return_value.properties = {
+        "notes_for_surveyor": "Void || Key safe code 1234"
+    }
+
+    # Act
+    result = orchestrator.sync_tenant_data(PLACE_REF, deal_id=DEAL_ID)
+
+    # Assert
+    assert result == PropertyReportedVoid(place_ref=PLACE_REF)
+    assert sdk_client.crm.deals.basic_api.update.mock_calls == []
+
+
+def test_a_failed_void_flag_write_fails_the_sync_rather_than_reporting_success(
+    orchestrator: AbriOrchestrator,
+    mock_session: MagicMock,
+    sdk_client: MagicMock,
+) -> None:
+    # Arrange: nothing was created for a void property, so the whole flow is
+    # safe to re-run — the failure must reach the caller and be redelivered.
+    mock_session.post.return_value.content = _load_fixture(
+        "abri_relay_getscstenantdata_notenancyfound_response.xml"
+    )
+    sdk_client.crm.deals.basic_api.get_by_id.return_value.properties = {
+        "notes_for_surveyor": ""
+    }
+    api_error = DealsApiException(status=400, reason="Bad Request")
+    api_error.body = json.dumps({"category": "VALIDATION_ERROR"})
+    api_error.headers = {}
+    sdk_client.crm.deals.basic_api.update.side_effect = api_error
+
+    # Act / Assert
+    with pytest.raises(HubspotRequestError):
+        orchestrator.sync_tenant_data(PLACE_REF, deal_id=DEAL_ID)