If an ISF is received by CBP with the same B/L # and ISF Importer Number as one submitted in a previous ISF by a different filer, CBP accepts the duplicate ISF with a warning to let the filer know that a different party previously filed an ISF against the same shipment.

A status message with an S7 disposition code and a “DUPLICATE ISF BY ANOTHER FILER” description will be sent to the initial ISF filer indicating that a duplicate ISF was filed.

CBP expects the parties involved to contact the ISF importer in order to ascertain which ISF is the accurate one.