Collect the 10 importer-provided data elements: importer of record number, consignee number, seller name and address, buyer name and address, ship-to party, manufacturer (supplier) name and address, country of origin, HTS number (minimum 6 digits), container stuffing location, and consolidator name and address.
Submit the ISF to CBP no later than 24 hours before the cargo is loaded onto the vessel at the foreign port; late filing triggers liquidated damages of up to $5,000 per violation.
Transmit the filing electronically through the Automated Commercial Environment (ACE) via the Automated Broker Interface (ABI) — most importers engage a licensed customs broker or a compliance software provider (e.g., Descartes, CargoSmart) to make the ABI submission on their behalf.
The carrier must separately submit 2 additional data elements (vessel stow plan and container status messages) — these are the '2' in 10+2 and are the carrier's responsibility, not the importer's.
After CBP receives the ISF, update the filing with any changes to HTS codes, container stuffing location, or consolidator before vessel departure — amendments are permitted and strongly preferred over submitting with known errors.
Retain the ISF confirmation number and ACE transaction ID against the ocean shipment record; CBP may request the ISF number during import examination or as part of a post-entry audit.
Known gotchas
The 24-hour pre-loading deadline is measured at the foreign load port, not at a US port — for LCL (consolidation) shipments, the stuffing location and consolidator data are often not finalized 24 hours before loading, creating a common compliance gap.
Post-August 2025 CBP enforcement has tightened on ISF compliance given the elimination of de minimis for many shipments — previously low-value shipments that bypassed formal entry now require both ISF and formal entry, and under-resourced importers are accruing penalties.
An ISF filed with a placeholder or estimated HTS code that does not match the final customs entry HTS code constitutes an inaccurate filing — use the most precise 6-digit code available at ISF time and amend promptly when final classification is confirmed.
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp