diff --git a/hellosign_sdk/hsclient.py b/hellosign_sdk/hsclient.py
index 5af025c..72c0b66 100644
--- a/hellosign_sdk/hsclient.py
+++ b/hellosign_sdk/hsclient.py
@@ -2116,7 +2116,8 @@ def _send_signature_request_with_template(self, test_mode=False, client_id=None,
             "message": message,
             "signing_redirect_url": signing_redirect_url,
             "allow_decline": self._boolean(allow_decline),
-            "signing_options": HSFormat.format_json_data(signing_options)
+            "signing_options": HSFormat.format_json_data(signing_options),
+            "custom_fields": HSFormat.format_json_data(custom_fields)
 
         }