What the Importer Security Filing is
The Importer Security Filing (ISF) is the advance cargo data that U.S. Customs and Border Protection (CBP) requires for goods arriving in the United States by ocean vessel, and the core of it must be filed no later than 24 hours before the cargo is loaded onto the ship at the foreign port. For a container leaving Shanghai, Ningbo or Shenzhen, that means the filing is due before the box goes on board in China, not when it reaches a U.S. port.
The ISF is commonly called "10+2": ten data elements from the importer and two from the ocean carrier. The rule is 19 CFR Part 149, issued by CBP Dec. 08-46 (73 FR 71782, 25 November 2008), with a compliance date of 26 January 2010. As of October 2026, no change to Part 149 was identified in the research behind this page.
The ISF applies to vessel cargo only. Air shipments do not need one; air cargo falls under ACAS (Air Cargo Advance Screening), a separate regime. The ISF is also distinct from the customs entry. It is security data filed before departure; the entry and entry summary that release the goods and pay the duty come later, although the two can be transmitted together.
Who files the ISF
The obligation sits with the ISF importer, defined in 19 CFR 149.1 as the party causing the goods to arrive in the United States by vessel. That may be the owner, purchaser or consignee of the goods, or an agent acting for them, such as a licensed customs broker. For foreign cargo remaining on board (FROB) that is not being entered in the United States, the carrier or NVOCC (non-vessel-operating common carrier) is the ISF importer.
On a typical FOB purchase from China, the U.S. buyer is the ISF importer, and its customs broker or forwarder usually transmits the filing through CBP's Automated Commercial Environment (ACE). On a DDP (Delivered Duty Paid) shipment, the question is who is causing the goods to arrive, which is why the ISF importer and the importer of record on a DDP arrangement need to be agreed in writing before the goods ship.
Every ISF must be covered by a bond. Under 19 CFR 149.5(b), that can be the ISF importer's own bond or the filing agent's. A continuous customs bond covers ISF obligations.
The ten importer elements and the two carrier elements
19 CFR 149.3(a) lists the ten elements the ISF importer must supply:
- Seller.
- Buyer.
- Importer of record number, or foreign-trade zone applicant identification number.
- Consignee number(s).
- Manufacturer (or supplier).
- Ship-to party.
- Country of origin.
- Commodity HTSUS number, to at least six digits.
- Container stuffing location — where the goods were loaded into the container.
- Consolidator (stuffer) — the party that stuffed the container.
The "+2" are the carrier's vessel stow plan and container status messages. Those are carrier obligations under CBP's vessel regulations in 19 CFR Part 4, not Part 149; the specific section numbers were not re-checked for this page.
Several elements require information only the China side has. The manufacturer, the stuffing location and the consolidator must come from the supplier or the origin forwarder. When the seller is a trading company, the manufacturer element still calls for the factory that made the goods where it is known, which is one practical reason to know whether you are buying from a factory or a trader.
Deadlines, flexibility and updates
The timing rules are in 19 CFR 149.2:
- Elements 1–8 are due no later than 24 hours before the cargo is laden aboard the vessel at the foreign port.
- Elements 9 and 10, the stuffing location and consolidator, are due as early as possible and no later than 24 hours before the vessel arrives at a U.S. port.
Four elements may be filed on the best information available at the time and updated later: manufacturer or supplier, ship-to party, country of origin and HTSUS number. They must be updated as soon as better information is known, and no later than 24 hours before arrival at a U.S. port (19 CFR 149.2(c)–(d)).
The filing is not a one-time event. If any information changes before the goods enter the limits of a U.S. port, the ISF must be updated. If the goods are no longer destined for the United States, it must be withdrawn.
The 24-hour-before-loading rule is the one that catches China importers. A supplier or origin forwarder that is slow to send the seller, manufacturer and shipping details can push the ISF past its deadline even when the goods themselves are fully compliant.
ISF-5 and the shipments with different rules
Some vessel cargo passes through or near the United States without being entered for consumption. For those shipments, 19 CFR 149.3(b) requires a shorter filing, often called ISF-5: five elements instead of ten. It applies to:
- foreign cargo remaining on board (FROB);
- immediate exportation (IE) shipments;
- transportation and exportation (T&E) shipments.
The five elements are the booking party, the foreign port of unlading, the place of delivery, the ship-to party and the HTSUS number.
Two further categories are treated differently under 19 CFR 149.4. Bulk cargo that is exempt from the carrier's cargo declaration requirement is exempt from ISF. Qualifying break bulk cargo has a later deadline: 24 hours before arrival rather than before loading.
LCL (less-than-container-load) cargo is not exempt. It is vessel cargo, it needs an ISF, and the consolidator element is the party that stuffed the shared container.
Penalties and enforcement
An ISF failure is a breach of the basic importation bond. Under 19 CFR 113.62(j), CBP may assess liquidated damages of $5,000 per violation against the bond. A late filing is a violation even if every element in it is correct and the goods are fully admissible.
CBP matches the ISF against the carrier's bill of lading data. A missing, late or inaccurate ISF can also lead to cargo holds and examinations, which add storage and exam costs on top of any liquidated damages.
Liquidated damages may be mitigated under CBP guidelines, but the current guideline amounts could not be confirmed for this page. Whether CBP announced stepped-up ISF enforcement or revised mitigation guidelines in 2025 or 2026 was also not confirmed. Plan on the $5,000 figure in the regulation, not on mitigation.
How the ISF connects to the entry
The ISF and the customs entry describe the same goods, and CBP compares them. When the two are transmitted together as a combined ISF and entry filing, the importer of record number, consignee number, country of origin and ten-digit HTSUS number are supplied once (19 CFR 149.6).
The HTSUS number is the element that most often drifts. The ISF accepts six digits; the entry requires ten, plus any Chapter 99 lines for Section 301 duties. A six-digit ISF code that does not match the subheading eventually used on the entry, or an ISF country of origin that differs from the entry, is a discrepancy CBP can see.
Common ISF mistakes on China shipments
- Naming the trading company as manufacturer. The element calls for the manufacturer, or supplier; use the factory where it is known.
- Filing after the vessel has sailed. A late filing is a violation on its own.
- Not completing the stuffing location and consolidator by 24 hours before U.S. arrival.
- Mismatches with the entry in HTSUS subheading or country of origin.
- Assuming air shipments need an ISF. They do not; air cargo uses ACAS.
- Assuming the forwarder has filed it. The ISF importer carries the obligation, whoever transmits the data.
Frequently asked questions
What is ISF 10+2?
ISF 10+2 is the Importer Security Filing CBP requires for vessel cargo bound for the United States: ten data elements from the importer under 19 CFR 149.3(a) and two from the ocean carrier, the vessel stow plan and container status messages. The importer's elements include seller, buyer, manufacturer, country of origin, a six-digit HTSUS number, stuffing location and consolidator.
When is the ISF due?
The first eight importer elements are due no later than 24 hours before the cargo is loaded onto the vessel at the foreign port, under 19 CFR 149.2(b). The container stuffing location and consolidator are due as early as possible and no later than 24 hours before the vessel arrives at a U.S. port. For China shipments, the main deadline falls before departure.
What is the penalty for a late or missing ISF?
Liquidated damages of $5,000 per violation against the importer's bond, under 19 CFR 113.62(j). A late filing counts as a violation even if the information is accurate and the goods are compliant. A missing or inaccurate ISF can also lead to cargo holds and examinations. CBP has mitigation guidelines, but current amounts could not be confirmed.
Who is responsible for filing the ISF?
The ISF importer, defined in 19 CFR 149.1 as the party causing the goods to arrive in the United States by vessel, such as the owner, purchaser or consignee, or an agent like a licensed customs broker. On an FOB purchase from China, that is usually the U.S. buyer, with its broker or forwarder transmitting the data.
Do air shipments from China need an ISF?
No. The Importer Security Filing applies only to cargo arriving by ocean vessel under 19 CFR Part 149. Air cargo is covered by a separate advance data regime, ACAS (Air Cargo Advance Screening). An air shipment still needs a customs entry, but not an ISF, and the Harbor Maintenance Fee also does not apply to air cargo.
Do I need a bond to file an ISF?
Yes. Under 19 CFR 149.5(b), each ISF must be covered by a bond, which can be the ISF importer's own bond or the bond of the agent filing it. A continuous customs bond covers ISF obligations. ISF compliance is a condition of the basic importation bond, which is why ISF liquidated damages are claimed against it.
Does LCL cargo need an ISF?
Yes. Less-than-container-load cargo arrives by vessel, so it needs an Importer Security Filing like a full container. The consolidator element under 19 CFR 149.3(a)(10) is the party that stuffed the shared container, and the stuffing location is where that happened. Those two details usually come from the origin forwarder or consolidator in China.