diff --git a/src/Validator.php b/src/Validator.php
index 0afe7f2..45d94d3 100644
--- a/src/Validator.php
+++ b/src/Validator.php
@@ -50,7 +50,8 @@ class Validator
         'RO' => '\d{2,10}',
         'SE' => '\d{12}',
         'SI' => '\d{8}',
-        'SK' => '\d{10}'
+        'SK' => '\d{10}',
+        'XI' => '\d{9,12}|(GD|HA)\d{3}'
     );
 
     /**