diff --git a/docs/source/json-api/index.rst b/docs/source/json-api/index.rst
index 87183aee50c0..382cb56ac94d 100644
--- a/docs/source/json-api/index.rst
+++ b/docs/source/json-api/index.rst
@@ -224,6 +224,8 @@ The **JSON API** can return one of the following HTTP status codes:
 - 500 - Internal Server Error
 - 503 - Service Unavailable, ledger server is not running yet or has been shut down
 
+When the Ledger API returns an error code, the JSON API maps it to one of the above codes according to `the official gRPC to HTTP code mapping <https://cloud.google.com/apis/design/errors#generating_errors>`_.
+
 If a client's HTTP GET or POST request reaches an API endpoint, the corresponding response will always contain a JSON object with a ``status`` field, either an ``errors`` or ``result`` field and an optional ``warnings``:
 
 .. code-block:: none