Importer Security Filing (ISF) is a mandatory security filing that must be submitted to the US Customs and Border Protection (CBP) by the importer of record or its authorised agent. The ISF provides detailed information about the cargo being imported into the US, including the ship, voyage, consignee, manufacturer, commodity description, and value. The purpose of the ISF is to enhance security and reduce the risk of smuggling, terrorism, and other threats to US national security. The ISF must be filed prior to the departure of the ship carrying the cargo, and any changes to the information must be reported promptly to the CBP.