diff --git a/src/Validator.php b/src/Validator.php
index 45d94d3..b2d4dc9 100644
--- a/src/Validator.php
+++ b/src/Validator.php
@@ -24,7 +24,7 @@ class Validator
         'AT' => 'U[A-Z\d]{8}',
         'BE' => '[0|1]{1}\d{9}',
         'BG' => '\d{9,10}',
-        'CH' => 'E(-| ?)(\d{3}(\.)\d{3}(\.)\d{3}|\d{9})( ?)(MWST|TVA|IVA)',
+        'CH' => 'E(-| ?)(\d{3}(\.)\d{3}(\.)\d{3}|\d{9})( ?)(MWST|TVA|IVA)?',
         'CY' => '\d{8}[A-Z]',
         'CZ' => '\d{8,10}',
         'DE' => '\d{9}',