ISF 10+2 Filing: Deadlines, Data and Penalties Explained

Almost every ocean import into the United States needs an Importer Security Filing, better known as ISF or “10+2.” It is a small filing with outsized consequences: miss it, file it late, or file it wrong and you are looking at penalties, holds, and a container sitting at the terminal accruing charges.

This guide covers what ISF is, the data you need, when it is due, what happens when it goes wrong, and how to keep it from becoming a recurring problem.

What is ISF 10+2?

ISF is a U.S. Customs and Border Protection requirement that applies to cargo arriving in the United States by ocean vessel. The importer of record (or their agent) transmits a set of data elements to CBP before the cargo is loaded overseas, so CBP can assess risk before the container is on the water rather than after it arrives.

The “10+2” nickname comes from the split: ten data elements are the importer’s responsibility, and two are the ocean carrier’s. It does not apply to air, truck, or rail shipments — those have their own advance data requirements.

The importer’s ten elements

• Seller name and address
• Buyer name and address
• Importer of record number / FTZ applicant identification number
• Consignee number(s)
• Manufacturer or supplier name and address
• Ship-to party name and address
• Country of origin
• Commodity HTSUS number (to at least the 6-digit level)
• Container stuffing location
• Consolidator (stuffer) name and address

The carrier’s two elements

• Vessel stow plan
• Container status messages

You do not file the carrier’s two — but you do depend on the carrier doing their part, which is one reason a bad carrier relationship shows up as customs friction.

When is ISF due?

For standard cargo destined for the United States, the ISF must be transmitted no later than 24 hours before the cargo is laden aboard the vessel at the foreign port. That is 24 hours before loading, not 24 hours before arrival — a distinction that catches new importers every season.

Two of the ten elements, the container stuffing location and the consolidator, are treated with some flexibility because they are often not known 24 hours before lading. CBP allows them to be updated as soon as the information becomes available, but no later than 24 hours before arrival at a U.S. port. Several other elements may also be filed as a range and refined later. Confirm the current flexible-range rules with your broker, since CBP’s guidance is periodically updated.

The reduced filing for in-transit cargo

Cargo that is not entering U.S. commerce — freight remaining on board, and shipments moving under Immediate Exportation or Transportation and Exportation entries — requires a reduced set of five data elements rather than ten. If you move goods through the U.S. on their way somewhere else, see our overview of in-bond shipments and IT, T&E and IE entries.

Penalties: what non-compliance actually costs

CBP can assess liquidated damages of up to $5,000 per ISF violation, with a maximum of $10,000 per shipment when multiple violations stack. Violations include failing to file, filing late, filing inaccurate data, and failing to withdraw a filing that is no longer valid.

The penalty is not the only cost, and often not the biggest one. The practical consequences tend to be:

• “Do Not Load” messages — the carrier may be instructed not to load your container at origin, which means missing the sailing entirely.
• Holds on arrival — an ISF hold keeps the container at the terminal, where demurrage runs. Our guide on avoiding demurrage and detention at PortMiami explains how quickly those charges compound.
• Increased exam rates — a pattern of bad filings raises your risk profile, which means more of your future containers get looked at.

Who files, and who is responsible

The ISF importer — usually the importer of record, or the party causing the goods to enter for FROB and in-transit movements — is legally responsible. In practice, most companies have their customs broker or freight forwarder transmit the filing on their behalf.

Delegating the transmission does not delegate the liability. CBP holds the ISF importer accountable, and an ISF bond must be in place to cover potential liquidated damages. If your broker files late because your supplier sent the commercial invoice late, the penalty still lands on you.

How to stop ISF problems before they start

Fix the data at the source

Most late or inaccurate filings trace back to a supplier who sends documents slowly or inconsistently. Put the ISF data requirement in your purchase order terms, give suppliers a fixed template, and set an internal deadline that is earlier than the legal one.

Keep an ISF master file

Seller, manufacturer, and stuffing-location details rarely change between shipments from the same supplier. Maintaining a reference file per supplier turns a scramble into a lookup, and it makes errors easier to spot.

Reconcile ISF against the entry

The ISF should match what is ultimately filed on the entry. Mismatches between the ISF HTS code and the entered classification are a common trigger for review. Ask your broker to flag discrepancies rather than quietly correcting them.

Have a plan for when a hold lands anyway

Even clean importers get holds. The variable you control is how fast you react and where the freight goes afterward. A container freight station or a nearby warehouse with same-day devanning capability lets you clear the terminal quickly once the hold releases, instead of paying storage while you find a slot. If your Miami inbound flow is fragile, request a quote and we can look at where the delays are actually coming from.

Frequently asked questions

Does ISF apply to air freight?

No. ISF 10+2 applies to cargo arriving by ocean vessel. Air shipments are covered by separate advance electronic data requirements filed by the carrier or a qualified party, not by the ISF rule.

Can I amend an ISF after filing?

Yes. ISF filings can be updated, and CBP expects you to correct them as better information becomes available, up until the shipment arrives. What CBP penalizes is a filing that stays inaccurate — not one that gets corrected promptly.

Do I need a separate ISF bond?

You need bond coverage for the ISF. Importers with a continuous customs bond generally have ISF liability covered under it; importers using single-entry bonds typically need a separate single-transaction ISF bond for each filing. Your broker can confirm which applies to you.