diff --git a/intaro.retailcrm/classes/general/RCrmActions.php b/intaro.retailcrm/classes/general/RCrmActions.php
index 324a2eaa..351a4549 100644
--- a/intaro.retailcrm/classes/general/RCrmActions.php
+++ b/intaro.retailcrm/classes/general/RCrmActions.php
@@ -302,6 +302,17 @@ class RCrmActions
         return '';
     }
 
+    /**
+     * Returns true if provided externalId in new format (id_clientId)
+     *
+     * @param $externalId
+     * @return bool
+     */
+    public static function isNewExternalId($externalId)
+    {
+        return !(false === strpos($externalId, '_'));
+    }
+
     /**
      * Generates payment external ID
      *