In short: If you're shipping goods into the United States by ocean freight, US Customs and Border Protection requires an Importer Security Filing (ISF, also called "10+2") at least 24 hours before your cargo is loaded onto the vessel in China — not when it arrives in the US. Miss the deadline, file it incorrectly, or skip it altogether, and CBP can issue a liquidated damages penalty of up to $5,000 per violation. ISF filing doesn't apply to air freight, only ocean shipments, and it's usually filed by your customs broker or freight forwarder on your behalf once you give them the required supplier and product details.

Last updated: October 10, 2026

What Is ISF Filing (10+2)?

ISF stands for Importer Security Filing. It's a security measure CBP introduced so it can screen ocean cargo for risk before it even leaves the origin port — in this case, before it leaves China. It's nicknamed "10+2" because importers must submit 10 data elements, and the ocean carrier submits 2 more.

Who Is Responsible for Filing the ISF?

Technically, you — the importer of record — are responsible for ensuring the ISF is filed correctly and on time. In practice, almost every importer has their customs broker or freight forwarder file it on their behalf, using information the importer or their sourcing partner supplies before the shipment leaves China.

What Are the 10 Data Elements You Need to Provide?

Your broker will need the following before your goods are loaded onto the vessel:

• Seller (or owner) name and address
• Buyer (or owner) name and address
• Importer of record number
• Consignee number
• Manufacturer (or supplier) name and address
• Ship-to party name and address
• Country of origin
• Commodity HS code (Harmonized Tariff Schedule number)
• Container stuffing location
• Consolidator (stuffer) name and address

This is exactly why working with a sourcing partner who already has clean, verified supplier records makes ISF filing far less stressful — you're not scrambling for a factory's legal name and address the day before your container sails.

When Is the ISF Due?

What Happens If You File Late or Get It Wrong?

CBP can issue liquidated damages of $5,000 per violation, and in some cases up to $10,000 for multiple errors on the same shipment. Beyond the fine, an incomplete or late ISF is one of the most common reasons ocean shipments get flagged for inspection — which means extra delays and extra storage fees at the port while CBP reviews your cargo.

How Can You Avoid ISF Filing Mistakes?

Most ISF penalties come down to timing, not paperwork complexity. The fix is simple: get your final supplier and shipment details locked in early, well before your container is booked to sail, rather than trying to confirm them after the vessel schedule is already set. Working with a sourcing team that manages both the manufacturer relationship and the shipping documentation — rather than juggling two separate parties — removes most of the risk.

Frequently Asked Questions

Does ISF filing apply to air freight from China?

No. ISF filing is an ocean freight requirement only. Air freight and courier shipments (DHL, FedEx, UPS) don't require an ISF.

How far in advance do I need to file ISF?

At least 24 hours before your cargo is loaded onto the vessel at the Chinese port of departure — not 24 hours before it arrives in the US.

Who pays the ISF penalty if something goes wrong?

The importer of record is ultimately responsible, even if a broker or forwarder filed the ISF on their behalf. That's why accuracy at the source matters.

Do I need a customs bond to file an ISF?

Yes — CBP requires a bond in place before an ISF can be filed. Most importers use the same continuous bond that covers their regular customs entries.

Can I file my own ISF without a broker?

Technically yes, through CBP's Automated Broker Interface, but almost no small or mid-sized importer does this in practice — the filing requires specific software access, and a broker or forwarder typically includes it as part of standard ocean freight service.

How Epic Sourcing Helps

Because Epic Sourcing's bilingual teams manage your supplier relationship on the ground in China and Vietnam, the supplier names, addresses, and HS code details your broker needs for ISF filing are accurate and ready well before your container is booked — not chased down at the last minute. Learn more about our freight forwarding support, or talk to our team, no pressure, no obligation.

Related reading: what a proforma invoice is and why you need one, do you need a customs bond to import from China, and how China-based 3PL and fulfillment centers work.