diff --git a/specification/schemas/TaxIdentificationNumber.json b/specification/schemas/TaxIdentificationNumber.json
index e92a244..6b5879f 100644
--- a/specification/schemas/TaxIdentificationNumber.json
+++ b/specification/schemas/TaxIdentificationNumber.json
@@ -27,7 +27,8 @@
         "eori",
         "ioss",
         "vat",
-        "gst"
+        "gst",
+        "ukims"
       ]
     }
   }