Importer Security Filing (ISF) is a U.S. Customs and Border Protection advance filing requirement for cargo arriving by vessel. For standard ISF-10 filings, eight elements are generally required at least 24 hours before loading aboard a U.S.-bound vessel; the remaining two have separate timing rules. The ISF importer or its authorized agent files it, separately from the carrier’s manifest submission.
In practice, the filing relies on information from the commercial invoice, packing list, booking data, and transportation details. Because some fields may come from overseas suppliers or carriers, importers often coordinate closely with freight forwarders, customs brokers, and vendors to avoid missing or inconsistent data.
The ISF is specific to vessel cargo; it does not apply the same way to every mode of transport, and the responsible filing party can depend on the import arrangement. If the filing is late or inaccurate, the shipment may face delays, extra scrutiny, or other consequences under U.S. customs rules. For example, an importer bringing in containerized consumer goods from Asia would need to make sure the manufacturer, seller, ship-to party, and container stuffing information are assembled early enough to support the applicable filing deadlines.