The ISF importer is responsible for filing Importer Security Filing. The reason for this is that they are directly responsible for facilitating the arrival of cargo into an American port. Usually, the ISF importer is the owner of the goods, consignee, purchaser, or the customs broker or agent working on behalf of any of the parties.

Transit cargo of foreign cargo that remains on board the vessel (FROB), the carrier is the typical ISF importer. There is a subset of the data known as ISF (5) since the data requirements for transit and FROB cargo consist of five (5) data elements.