diff --git a/api/src/services/legal_entities.py b/api/src/services/legal_entities.py
index b90f1e9..dbab8c4 100644
--- a/api/src/services/legal_entities.py
+++ b/api/src/services/legal_entities.py
@@ -293,8 +293,10 @@ class LegalEntityService:
             if field not in data.model_fields_set:
                 continue
             value = getattr(data, field)
+            if value == getattr(entity, field):
+                continue  # то же значение — не изменение (Review Focus 1), даже если филиал ЮЛ чужой для пользователя
             if field == "regional_office_id":
-                value = office_for_create(self._scope, value)
+                value = office_for_create(self._scope, value)  # policy — только для фактической смены филиала
             if value != getattr(entity, field):
                 changes[field] = value
         if "entity_type" in changes:
diff --git a/api/tests/test_api_legal_entities.py b/api/tests/test_api_legal_entities.py
index 02bd935..9f36cab 100644
--- a/api/tests/test_api_legal_entities.py
+++ b/api/tests/test_api_legal_entities.py
@@ -533,3 +533,33 @@ async def test_failed_move_rolls_back_everything(
     assert reloaded_member.valid_to is None
     assert await _history_count(seeded) == 0
     assert not await _events(seeded, AuditAction.LEGAL_ENTITY_CHANGE, AuditAction.MEMBERSHIP_CHANGE)
+
+
+@pytest.mark.integration
+async def test_branch_patch_with_unchanged_foreign_office_is_not_rejected(
+    auth_client: AuthClientFactory, seeded: AsyncSession
+) -> None:
+    """I-1 (Review Focus 1): ЮЛ в ГК своего филиала с чужим `regional_office_id`; форма шлёт тот же филиал — не 422."""
+    rostov, krasnodar = await _office(seeded, ROSTOV), await _office(seeded, KRASNODAR)
+    group = await make_company_group(seeded, name="ГК Ростов", office=rostov)
+    entity = await make_legal_entity(seeded, name="ООО Старое", group=group, office=krasnodar)  # как создал бы ГО
+    client = await auth_client("ka_rf@armka.local")
+
+    same_office_only = await client.patch(f"{ENTITIES}/{entity.id}", json={"regional_office_id": str(krasnodar.id)})
+    assert same_office_only.status_code == HTTP_OK, same_office_only.text
+    assert same_office_only.json()["regional_office_id"] == str(krasnodar.id)
+    assert await _history_count(seeded) == 0
+    assert not await _events(seeded, AuditAction.LEGAL_ENTITY_CHANGE)
+
+    renamed = await client.patch(
+        f"{ENTITIES}/{entity.id}", json={"name": "ООО Новое", "regional_office_id": str(krasnodar.id)}
+    )
+    assert renamed.status_code == HTTP_OK, renamed.text
+    assert (renamed.json()["name"], renamed.json()["regional_office_id"]) == ("ООО Новое", str(krasnodar.id))
+    assert await _history_count(seeded) == 1
+    (event,) = await _events(seeded, AuditAction.LEGAL_ENTITY_CHANGE)
+    assert (event.before_value, event.after_value) == ({"name": "ООО Старое"}, {"name": "ООО Новое"})
+
+    to_foreign = await client.patch(f"{ENTITIES}/{entity.id}", json={"regional_office_id": None})
+    assert to_foreign.status_code == HTTP_OK  # явный null у филиала — свой филиал (это изменение)
+    assert to_foreign.json()["regional_office_id"] == str(rostov.id)