diff --git a/airbyte_cdk/sources/streams/http/error_handlers/default_error_mapping.py b/airbyte_cdk/sources/streams/http/error_handlers/default_error_mapping.py
index 45716768f..910951c8d 100644
--- a/airbyte_cdk/sources/streams/http/error_handlers/default_error_mapping.py
+++ b/airbyte_cdk/sources/streams/http/error_handlers/default_error_mapping.py
@@ -30,8 +30,8 @@
     ),
     400: ErrorResolution(
         response_action=ResponseAction.FAIL,
-        failure_type=FailureType.system_error,
-        error_message="HTTP Status Code: 400. Error: Bad request. Please check your request parameters.",
+        failure_type=FailureType.config_error,
+        error_message=None,
     ),
     401: ErrorResolution(
         response_action=ResponseAction.FAIL,
diff --git a/airbyte_cdk/sources/streams/http/http_client.py b/airbyte_cdk/sources/streams/http/http_client.py
index 3a0a62739..208f7814e 100644
--- a/airbyte_cdk/sources/streams/http/http_client.py
+++ b/airbyte_cdk/sources/streams/http/http_client.py
@@ -466,21 +466,34 @@ def _handle_error_resolution(
 
         if error_resolution.response_action == ResponseAction.FAIL:
             if response is not None:
+                parsed_api_error = self._error_message_parser.parse_response_error_message(response)
                 filtered_response_message = filter_secrets(
                     f"Request (body): '{str(request.body)}'. Response (body): '{self._get_response_body(response)}'. Response (headers): '{response.headers}'."
                 )
-                error_message = f"'{request.method}' request to '{request.url}' failed with status code '{response.status_code}' and error message: '{self._error_message_parser.parse_response_error_message(response)}'. {filtered_response_message}"
+                error_message = f"'{request.method}' request to '{request.url}' failed with status code '{response.status_code}' and error message: '{parsed_api_error}'. {filtered_response_message}"
+
+                # Build user-facing message: prefer the error handler's custom message,
+                # fall back to a concise message with the parsed API error body
+                if error_resolution.error_message:
+                    user_facing_message = error_resolution.error_message
+                elif parsed_api_error:
+                    user_facing_message = filter_secrets(
+                        f"API responded with HTTP {response.status_code}: {parsed_api_error}"
+                    )
+                else:
+                    user_facing_message = f"API responded with HTTP {response.status_code}."
             else:
                 error_message = (
                     f"'{request.method}' request to '{request.url}' failed with exception: '{exc}'"
                 )
+                user_facing_message = error_resolution.error_message or error_message
 
             # ensure the exception message is emitted before raised
             self._logger.error(error_message)
 
             raise AirbyteTracedException(
                 internal_message=error_message,
-                message=error_resolution.error_message or error_message,
+                message=user_facing_message,
                 failure_type=error_resolution.failure_type,
             )
 
diff --git a/unit_tests/sources/declarative/requesters/error_handlers/test_default_error_handler.py b/unit_tests/sources/declarative/requesters/error_handlers/test_default_error_handler.py
index bf4e1e321..0f5e73541 100644
--- a/unit_tests/sources/declarative/requesters/error_handlers/test_default_error_handler.py
+++ b/unit_tests/sources/declarative/requesters/error_handlers/test_default_error_handler.py
@@ -91,8 +91,8 @@ def test_default_error_handler_with_default_response_filter(
                 parameters={},
             ),
             ResponseAction.RETRY,
-            FailureType.system_error,
-            "HTTP Status Code: 400. Error: Bad request. Please check your request parameters.",
+            FailureType.config_error,
+            None,
         ),
         (
             "_with_http_response_status_402_fail_with_default_failure_type",
diff --git a/unit_tests/sources/mock_server_tests/test_resumable_full_refresh.py b/unit_tests/sources/mock_server_tests/test_resumable_full_refresh.py
index 04e232083..2b881fcd6 100644
--- a/unit_tests/sources/mock_server_tests/test_resumable_full_refresh.py
+++ b/unit_tests/sources/mock_server_tests/test_resumable_full_refresh.py
@@ -370,6 +370,6 @@ def test_resumable_full_refresh_failure(self, http_mocker):
             page=2
         )
 
-        assert actual_messages.errors[0].trace.error.failure_type == FailureType.system_error
+        assert actual_messages.errors[0].trace.error.failure_type == FailureType.config_error
         assert actual_messages.errors[0].trace.error.stream_descriptor.name == "justice_songs"
-        assert "Bad request" in actual_messages.errors[0].trace.error.message
+        assert "400" in actual_messages.errors[0].trace.error.message