On April 10, 2017 U.S. Customs and Border (CBP) issued Cargo Release Messaging Service (CSMS) #17-000204 announcing changes to the use of Standard Carrier Alpha Code (SCAC) “UNKN” for both AMS and non-AMS bill types in ACE.
According to the CSMS, UNKN will now be rejected if used in either AMS or non-AMS bill types. If you are entering a non-AMS bill type, the use of SCAC “ZZZZ” will be permitted temporarily as a workaround to this new programming. The use of “ZZZZ” will not be allowed in manifest or in-bond transactions.
The CSMS can be accessed at:
https://apps.cbp.gov/csms/viewmssg.asp?Recid=22606&page=&srch_argv=&srchtype=&btype=&sortby=&sby=
