What Is Importer Security Filing (ISF)?

The Importer Security Filing (ISF), also known as the “10+2” rule, is a U.S. Customs and Border Protection (CBP) requirement that applies to all cargo being imported into the United States by ocean vessel. It was introduced in 2009 to enhance supply chain security and allow CBP to assess risk before goods arrive at U.S. ports.

If you are importing from China (or any country) to the U.S. by sea, ISF filing is mandatory.

What Does ISF “10+2” Mean?

• 10 data elements from the importer (to be filed by the importer or their customs broker):

1. Seller

2. Buyer

3. Importer of Record Number

4. Consignee Number(s)

5. Manufacturer (or Supplier)

6. Ship to Party

7. Country of Origin

8. Commodity Harmonized Tariff Schedule (HTSUS) number

9. Container stuffing location

10. Consolidator (stuffer)

• 2 data elements from the carrier:

1. Vessel stow plan

2. Container status messages

When Must ISF Be Filed?

• At least 24 hours before cargo is loaded onto the vessel at the foreign port of origin (e.g., Shanghai, Shenzhen, Ningbo when shipping from China).

• Filed electronically through CBP-approved systems (usually by a licensed customs broker or freight forwarder).

Consequences of Not Filing ISF

• Fines/Penalties: Up to $5,000 per violation.

• Cargo Holds/Delays: Shipments may be held at the port, inspected, or refused entry.

• Increased Costs: Storage, demurrage, and inspection fees can add up quickly.

Best Practices for Importers

1. Work with a Licensed Customs Broker – They ensure timely and accurate filings.

2. Coordinate Early with Suppliers – Make sure manufacturers in China provide required data well before cargo is loaded.

3. Double-Check Data Accuracy – Incorrect details can trigger penalties even if the filing is on time.

4. Keep Compliance Records – Maintain ISF records for at least five years as required by CBP.

In short: ISF is a mandatory pre-arrival filing for all ocean imports into the U.S. from China or elsewhere. Getting it right means smoother customs clearance, fewer delays, and lower risk of penalties.