diff --git a/etl/hubspot/hubspot_deal_differ.py b/etl/hubspot/hubspot_deal_differ.py
index 68b075182..c4e9c0148 100644
--- a/etl/hubspot/hubspot_deal_differ.py
+++ b/etl/hubspot/hubspot_deal_differ.py
@@ -187,6 +187,25 @@ class HubspotDealDiffer:
 
         return parse_hs_date(new_deal.get("confirmed_survey_date")) is not None
 
+    @staticmethod
+    def check_for_abri_survey_amendment(
+        new_deal: Dict[str, str],
+        new_project: Optional[ProjectData],
+        old_deal: HubspotDealData,
+    ) -> bool:
+        if not HubspotDealDiffer._is_abri_condition_deal(new_deal, new_project):
+            return False
+
+        # A first-time survey date is a creation, not an amendment.
+        if old_deal.confirmed_survey_date is None:
+            return False
+
+        new_survey_date = parse_hs_date(new_deal.get("confirmed_survey_date"))
+        if old_deal.confirmed_survey_date != new_survey_date:
+            return True
+
+        return old_deal.confirmed_survey_time != new_deal.get("confirmed_survey_time")
+
     @staticmethod
     def _is_abri_condition_deal(
         new_deal: Dict[str, str], new_project: Optional[ProjectData]
diff --git a/etl/hubspot/tests/test_hubspot_deal_differ.py b/etl/hubspot/tests/test_hubspot_deal_differ.py
index a072b175f..544242623 100644
--- a/etl/hubspot/tests/test_hubspot_deal_differ.py
+++ b/etl/hubspot/tests/test_hubspot_deal_differ.py
@@ -548,6 +548,145 @@ def test_abri_survey_creation__non_abri_project_id_with_abri_code__returns_false
     assert result is False
 
 
+# ===================================
+# ABRI SURVEY AMENDMENT TRIGGER TESTS
+# ===================================
+
+
+def test_abri_survey_amendment__date_changed_on_abri_deal__returns_true() -> None:
+    deal_id = uuid.uuid4()
+
+    # Arrange
+    old_deal = make_old_deal(
+        id=deal_id,
+        project_code="Abri Condition",
+        confirmed_survey_date=datetime(2026, 7, 1, tzinfo=timezone.utc),
+    )
+    new_deal = make_new_deal(
+        deal_id,
+        project_code="Abri Condition",
+        confirmed_survey_date="2026-07-15",
+    )
+
+    # Act
+    result = HubspotDealDiffer.check_for_abri_survey_amendment(
+        new_deal=new_deal,
+        new_project=None,
+        old_deal=old_deal,
+    )
+
+    # Assert
+    assert result is True
+
+
+def test_abri_survey_amendment__non_abri_deal__returns_false() -> None:
+    deal_id = uuid.uuid4()
+
+    # Arrange
+    old_deal = make_old_deal(
+        id=deal_id,
+        project_code="Southern Retrofit",
+        confirmed_survey_date=datetime(2026, 7, 1, tzinfo=timezone.utc),
+    )
+    new_deal = make_new_deal(
+        deal_id,
+        project_code="Southern Retrofit",
+        confirmed_survey_date="2026-07-15",
+    )
+
+    # Act
+    result = HubspotDealDiffer.check_for_abri_survey_amendment(
+        new_deal=new_deal,
+        new_project=None,
+        old_deal=old_deal,
+    )
+
+    # Assert
+    assert result is False
+
+
+def test_abri_survey_amendment__date_and_time_unchanged__returns_false() -> None:
+    deal_id = uuid.uuid4()
+
+    # Arrange
+    old_deal = make_old_deal(
+        id=deal_id,
+        project_code="Abri Condition",
+        confirmed_survey_date=datetime(2026, 7, 15, tzinfo=timezone.utc),
+        confirmed_survey_time="09:30",
+    )
+    new_deal = make_new_deal(
+        deal_id,
+        project_code="Abri Condition",
+        confirmed_survey_date="2026-07-15",
+        confirmed_survey_time="09:30",
+    )
+
+    # Act
+    result = HubspotDealDiffer.check_for_abri_survey_amendment(
+        new_deal=new_deal,
+        new_project=None,
+        old_deal=old_deal,
+    )
+
+    # Assert
+    assert result is False
+
+
+def test_abri_survey_amendment__time_changed_on_abri_deal__returns_true() -> None:
+    deal_id = uuid.uuid4()
+
+    # Arrange
+    old_deal = make_old_deal(
+        id=deal_id,
+        project_code="Abri Condition",
+        confirmed_survey_date=datetime(2026, 7, 15, tzinfo=timezone.utc),
+        confirmed_survey_time="09:30",
+    )
+    new_deal = make_new_deal(
+        deal_id,
+        project_code="Abri Condition",
+        confirmed_survey_date="2026-07-15",
+        confirmed_survey_time="14:00",
+    )
+
+    # Act
+    result = HubspotDealDiffer.check_for_abri_survey_amendment(
+        new_deal=new_deal,
+        new_project=None,
+        old_deal=old_deal,
+    )
+
+    # Assert
+    assert result is True
+
+
+def test_abri_survey_amendment__date_first_set_on_abri_deal__returns_false() -> None:
+    deal_id = uuid.uuid4()
+
+    # Arrange
+    old_deal = make_old_deal(
+        id=deal_id,
+        project_code="Abri Condition",
+        confirmed_survey_date=None,
+    )
+    new_deal = make_new_deal(
+        deal_id,
+        project_code="Abri Condition",
+        confirmed_survey_date="2026-07-15",
+    )
+
+    # Act
+    result = HubspotDealDiffer.check_for_abri_survey_amendment(
+        new_deal=new_deal,
+        new_project=None,
+        old_deal=old_deal,
+    )
+
+    # Assert
+    assert result is False
+
+
 # =======================
 # DB UPDATE TRIGGER TESTS
 # =======================