The ISF “10+2” Filing Guide for Miami Ocean Importers (2026)

If you import ocean freight into PortMiami or Port Everglades, the Importer Security Filing — better known as ISF or “10+2” — is one of those requirements that’s easy to get right and expensive to get wrong. File it accurately and on time and you’ll rarely think about it. Miss it, and you’re looking at liquidated damages of $5,000 per violation, cargo holds, and increased exam rates on future shipments.

This guide covers what the ISF actually requires, when it’s due, who’s responsible, and how a customs-focused 3PL keeps Miami importers out of trouble.

What is the Importer Security Filing?

The ISF is a security data submission required by U.S. Customs and Border Protection for ocean cargo arriving in the United States. It exists so CBP can assess risk before a container is ever loaded onto a vessel overseas — not after it shows up at a U.S. terminal.

The nickname “10+2” comes from the structure: the importer (or their agent) supplies ten data elements, and the ocean carrier supplies two more. The rule applies to ocean freight only — air, truck, and rail shipments are not subject to ISF.

The 10 importer data elements

For standard import shipments (sometimes called “ISF-10”), the importer or its filing agent must submit:

1. Seller — name and address of the last known seller of the goods
2. Buyer — name and address of the last known buyer
3. Importer of record number — IRS/EIN, SSN, or CBP-assigned number
4. Consignee number(s) — for the party the goods are consigned to
5. Manufacturer (or supplier) — name and address
6. Ship-to party — the first delivery location in the U.S., such as your warehouse or distribution point
7. Country of origin — of the merchandise
8. Commodity HTSUS number — to at least the 6-digit level
9. Container stuffing location — where the goods were loaded into the container
10. Consolidator (stuffer) — the party who stuffed the container or arranged it

The first eight elements must be filed no later than 24 hours before the cargo is laden aboard the vessel at the foreign port. The last two — container stuffing location and consolidator — are “flexible” elements that may be updated as late as 24 hours prior to the vessel’s arrival in the U.S., though best practice is to file everything together, accurately, up front.

The +2 carrier elements

The ocean carrier is responsible for two submissions:

• Vessel stow plan — showing where containers are positioned on the ship
• Container status messages (CSMs) — event data on container movements

As the importer, you don’t file these — but you should know they exist, because CBP cross-checks carrier data against your ISF. Discrepancies can trigger scrutiny.

The deadline that actually matters

The rule is simple and unforgiving: the ISF must be accepted by CBP at least 24 hours before the cargo is laden aboard the vessel at the origin port. Not 24 hours before arrival in Miami — 24 hours before loading overseas.

In practice, that means your ISF data needs to be assembled days earlier. Origin agents commonly need documents (commercial invoice, packing list, booking confirmation) 48–72 hours before the vessel cutoff to leave room for filing and correcting rejections. Miami importers buying from Asia face an added wrinkle: time zone gaps mean a “we’ll send it tomorrow” from your supplier can quietly turn into a missed lading deadline.

A special case worth knowing: shipments that will remain on board or move through the U.S. as in-bond exports (FROB, IE, and T&E cargo) require a shorter ISF-5 filing with five data elements rather than ten. If you route transshipment or re-export freight through South Florida, your filer should know which version applies.

What ISF penalties look like

CBP may assess liquidated damages of $5,000 per violation for ISF problems, including:

• Failure to file
• Late filing
• Inaccurate filing
• Failure to withdraw or amend an ISF when information changes

Multiple violations can stack on a single shipment, though CBP caps liquidated damages at $10,000 per ISF transaction. And the monetary penalty isn’t the only cost. ISF non-compliance commonly leads to:

• Cargo holds and exams at the first U.S. port, with exam fees, storage, and delays billed to you
• Increased targeting on future shipments once your record shows violations
• Do Not Load (DNL) messages in serious cases, keeping cargo off the vessel entirely

For an importer moving goods into a South Florida distribution operation on tight retail timelines, a single held container can cost far more in chargebacks and missed deliveries than the penalty itself.

Who is legally responsible?

The ISF importer — generally the party causing the goods to arrive in the U.S., typically the importer of record — bears legal responsibility, and a bond must be on file to cover the filing. You can (and most importers do) authorize an agent such as a customs broker or 3PL to transmit the filing, but delegation doesn’t transfer liability. If your filer misses the deadline, the liquidated damages claim still names you.

That’s the argument for working with a partner who treats ISF as part of an integrated process rather than an isolated data entry task.

How a 3PL and customs team keep you compliant

At Freight Hub Group, ISF compliance works best when it’s connected to everything that happens after the vessel sails. Here’s what that looks like in practice:

• Document discipline at origin. A standing SOP with your suppliers so invoices, packing lists, and stuffing details arrive on a fixed schedule — not whenever someone remembers.
• One data set, many uses. The same verified shipment data feeds the ISF, the customs entry, and the delivery order, so the HTS number on your ISF matches the one on your entry. Mismatches between the two are a classic exam trigger.
• Amendment management. Bookings roll, vessels change, quantities shift. ISFs must be updated when facts change, and a filer who monitors booking amendments catches these before CBP does.
• A plan for the container after arrival. ISF is step one of a chain. When the container discharges at PortMiami or Port Everglades, our container drayage fleet — with 300+ 40/45-foot chassis and 150+ 20-foot chassis — pulls it within free time, and our 100,000 sq ft Miami warehouse handles devanning, storage, or distribution. If an exam does happen, having the same team manage the recovery keeps the delay as short as possible.

A simple pre-sailing checklist for Miami importers

• ISF data collected at least 72 hours before vessel cutoff
• Importer of record number and bond confirmed active
• HTSUS numbers verified against the commercial invoice
• Ship-to party reflects the actual first U.S. delivery location
• Filing confirmation (ISF transaction number) received and saved
• Amendments filed for any booking or supplier changes

Frequently asked questions

When exactly is the ISF due?

The ISF must be accepted by CBP no later than 24 hours before the cargo is laden aboard the vessel at the foreign port of export. Two flexible elements — container stuffing location and consolidator — may be updated up to 24 hours before the vessel arrives in the U.S., but the core filing deadline is tied to loading overseas, not arrival in Miami.

How much is the ISF penalty?

CBP may assess liquidated damages of $5,000 per violation for a late, missing, or inaccurate ISF, capped at $10,000 per ISF transaction. Beyond the monetary claim, violations commonly lead to cargo holds, exams, and increased targeting of future shipments.

Can my freight forwarder or 3PL file the ISF for me?

Yes. Importers routinely authorize a customs broker, freight forwarder, or 3PL to transmit the ISF on their behalf. Keep in mind that legal responsibility stays with the ISF importer, so choose a filer with a documented process for collecting origin data early and amending filings when shipment details change.

Ready to tighten up your import compliance? Contact our team or call (786) 445-0150.