The Importer Security Filing (ISF) is a mandatory electronic submission to U.S. Customs and Border Protection that must be filed at least 24 hours before ocean cargo is loaded onto a vessel bound for the United States. Commonly referred to as "10+2" because the importer provides 10 data elements and the carrier provides 2, the ISF enables CBP to screen cargo for security risks before it reaches U.S. waters.
Why It Matters for Importers
Missing or late ISF filing is one of the most common — and most expensive — compliance failures in ocean freight importing. CBP assesses a $5,000 liquidated damages penalty for each ISF violation, and the fines are enforced aggressively. Beyond the financial penalty, a missing ISF can trigger CBP to hold your cargo at the port, issue a do-not-load order preventing your container from being placed on a vessel, or flag your company for increased inspections on future shipments.
The 24-hour filing deadline is absolute. If your ISF is not transmitted before the container is loaded at the foreign port, you are in violation regardless of the reason for the delay. This makes timely communication between the importer, supplier, and customs broker essential.
The 10 Importer Data Elements
- Seller name and address
- Buyer name and address
- Importer of record number
- Consignee number
- Manufacturer (or supplier) name and address
- Ship-to party name and address
- Country of origin
- HTS code (6-digit minimum)
- Container stuffing location
- Consolidator name and address
ISF Filing Best Practices
The most reliable way to avoid ISF penalties is to ensure your customs broker receives shipping documents — including the purchase order, commercial invoice, and packing list — at least 72 hours before the cargo is loaded. This buffer accounts for time zone differences, data verification, and any corrections needed before the 24-hour deadline.
Learn more about ISF requirements and how to build a compliant filing process in our ISF filing guide.