diff --git a/data_store/messaging/tf_messaging.py b/data_store/messaging/tf_messaging.py
index c5fd64035..c634616f4 100644
--- a/data_store/messaging/tf_messaging.py
+++ b/data_store/messaging/tf_messaging.py
@@ -300,7 +300,7 @@ def _wrong_type_failure_message(self, validation_failure: WrongTypeFailure) -> M
             [validation_failure.column] if isinstance(validation_failure.column, str) else validation_failure.column
         )
 
-        cell_index = tuple(
+        cell_index: tuple[str, ...] | None = tuple(
             self._construct_cell_index(
                 table=validation_failure.table,
                 column=column,
@@ -318,7 +318,7 @@ def _wrong_type_failure_message(self, validation_failure: WrongTypeFailure) -> M
             cell_index = (
                 (self._get_cell_indexes_for_outcomes(validation_failure.failed_row),)
                 if validation_failure.failed_row is not None
-                else ("",)
+                else None
             )
         if validation_failure.expected_type == datetime:
             message = self.msgs.WRONG_TYPE_DATE.format(wrong_type=actual_type)
@@ -388,7 +388,7 @@ def _non_nullable_constraint_failure_message(self, validation_failure: NonNullab
             [validation_failure.column] if isinstance(validation_failure.column, str) else validation_failure.column
         )
 
-        cell_index = tuple(
+        cell_index: tuple[str, ...] | None = tuple(
             self._construct_cell_index(
                 table=validation_failure.table,
                 column=column,
@@ -412,7 +412,7 @@ def _non_nullable_constraint_failure_message(self, validation_failure: NonNullab
                 cell_index = (
                     (self._get_cell_indexes_for_outcomes(validation_failure.failed_row),)
                     if validation_failure.failed_row is not None
-                    else ("",)
+                    else None
                 )
         elif sheet == "Funding Profiles":
             message = self.msgs.BLANK_ZERO
diff --git a/tests/data_store_tests/messaging_tests/test_tf_messaging.py b/tests/data_store_tests/messaging_tests/test_tf_messaging.py
index d6ab6744e..547df9d43 100644
--- a/tests/data_store_tests/messaging_tests/test_tf_messaging.py
+++ b/tests/data_store_tests/messaging_tests/test_tf_messaging.py
@@ -559,34 +559,6 @@ def test_failures_to_message_with_outcomes_column_amount():
     )
 
 
-def test_failures_to_message_with_outcomes_column_without_failed_row():
-    test_messger = TFMessenger()
-
-    failure1 = WrongTypeFailure(
-        table="Outcome_Data",
-        column="Amount",
-        expected_type=float,
-        actual_type=str,
-        row_index=23,
-        failed_row=None,
-    )
-
-    # message needs to have an index, which does not exist when failed_row is None
-    with pytest.raises(ValueError):
-        test_messger.to_message(failure1)
-
-    failure2 = NonNullableConstraintFailure(
-        table="Outcome_Data",
-        column="Amount",
-        row_index=60,
-        failed_row=None,
-    )
-
-    # message needs to have an index, which does not exist when failed_row is None
-    with pytest.raises(ValueError):
-        test_messger.to_message(failure2)
-
-
 def test_failures_to_message_with_duplicated_errors():
     test_messger = TFMessenger()
     failed_row1 = pd.Series({"Start_Date": pd.to_datetime("2023-05-01 12:00:00")}, name=60)