diff --git a/src/ga4gh/vrs/extras/translator.py b/src/ga4gh/vrs/extras/translator.py
index 81f38306..91c45532 100644
--- a/src/ga4gh/vrs/extras/translator.py
+++ b/src/ga4gh/vrs/extras/translator.py
@@ -142,8 +142,14 @@ def translate_to(self, vo: models._VariationBase, fmt: str, **kwargs) -> list[st
         kwargs:
             ref_seq_limit Optional(int):
                 If vo.state is a ReferenceLengthExpression, and `ref_seq_limit` is specified, and `fmt` is `spdi`, the reference sequence is included in the SPDI expression if it is below the limit Otherwise only the length of the reference sequence is included. If the limit is None, the reference sequence is always included. In all cases, the alt sequence is included. Default is 0 (never include reference sequence).
+        :raise NotImplementedError: If `fmt` is not supported
         """
-        t = self.to_translators[fmt]
+        try:
+            t = self.to_translators[fmt]
+        except KeyError as e:
+            msg = f"{fmt} is not supported"
+            raise NotImplementedError(msg) from e
+
         return t(vo, **kwargs)
 
     ############################################################################
diff --git a/tests/extras/test_allele_translator.py b/tests/extras/test_allele_translator.py
index 59b68862..15f87a89 100644
--- a/tests/extras/test_allele_translator.py
+++ b/tests/extras/test_allele_translator.py
@@ -978,20 +978,7 @@ def test_normalize_microsatellite_counts(tlr, case):
     )
 
 
-# TODO: Readd these tests
-# @pytest.mark.vcr
-# def test_errors(tlr):
-#     with pytest.raises(ValueError):
-#         tlr._from_beacon("bogus")
-#
-#     with pytest.raises(ValueError):
-#         tlr._from_gnomad("NM_182763.2:c.688+403C>T")
-#
-#     with pytest.raises(ValueError):
-#         tlr._from_hgvs("NM_182763.2:c.688+403C>T")
-#
-#     with pytest.raises(ValueError):
-#         tlr._from_hgvs("NM_182763.2:c.688_690inv")
-#
-#     with pytest.raises(ValueError):
-#         tlr._from_spdi("NM_182763.2:c.688+403C>T")
+@pytest.mark.vcr
+def test_translate_to_invalid_fmt(tlr):
+    with pytest.raises(NotImplementedError, match="gnomad is not supported"):
+        tlr.translate_to(models.Allele.model_validate(snv_output), fmt="gnomad")