diff --git a/resend/exceptions.py b/resend/exceptions.py
index 1d73491..e9c35c2 100644
--- a/resend/exceptions.py
+++ b/resend/exceptions.py
@@ -208,8 +208,14 @@ def __init__(
         "missing_required_fields": MissingRequiredFieldsError,
         "validation_error": ValidationError,
     },
-    "401": {"missing_api_key": MissingApiKeyError},
-    "403": {"invalid_api_key": InvalidApiKeyError},
+    "401": {
+        "missing_api_key": MissingApiKeyError,
+        "validation_error": ValidationError,
+    },
+    "403": {
+        "invalid_api_key": InvalidApiKeyError,
+        "validation_error": ValidationError,
+    },
     "429": {
         "rate_limit_exceeded": RateLimitError,
         "daily_quota_exceeded": RateLimitError,
diff --git a/tests/exceptions_test.py b/tests/exceptions_test.py
index 3d88cb0..2ffaa3b 100644
--- a/tests/exceptions_test.py
+++ b/tests/exceptions_test.py
@@ -47,6 +47,23 @@ def test_validation_error_from_400(self) -> None:
             raise_for_code_and_type(400, "validation_error", "err")
         assert e.type is ValidationError
 
+    def test_validation_error_from_401(self) -> None:
+        # Sending endpoints answer an invalid API key with 401 validation_error.
+        with pytest.raises(ValidationError) as e:
+            raise_for_code_and_type(401, "validation_error", "API key is invalid")
+        assert e.type is ValidationError
+        assert e.value.code == 401
+
+    def test_validation_error_from_403(self) -> None:
+        # An unverified sending domain is a 403 validation_error.
+        with pytest.raises(ValidationError) as e:
+            raise_for_code_and_type(
+                403, "validation_error", "The example.com domain is not verified."
+            )
+        assert e.type is ValidationError
+        assert e.value.code == 403
+        assert e.value.message == "The example.com domain is not verified."
+
     def test_error_500(self) -> None:
         with pytest.raises(ApplicationError) as e:
             raise_for_code_and_type(500, "application_error", "err")