How to File an ISF (Importer Security Filing): Step-by-Step

What Is the Importer Security Filing?

The Importer Security Filing (ISF), commonly known as '10+2,' is a CBP requirement that importers provide advance shipment information for all ocean cargo arriving in the United States. Implemented under the Security and Accountability for Every Port Act (SAFE Port Act), the ISF helps CBP assess the security risk of incoming shipments before they reach US shores. The '10+2' name comes from the 10 data elements required from the importer and 2 from the carrier. The ISF is required for ALL ocean shipments, regardless of value — there is no de minimis exemption.

Filing Deadlines

The ISF must be filed no later than 24 hours before the cargo is loaded onto the vessel at the foreign port of origin. This is not 24 hours before arrival in the US — it is 24 hours before loading overseas. For containerized cargo, this means you need all 10 data elements ready well before the vessel loading date. You can file as early as you want (even weeks before loading), and updates are allowed until 24 hours before arrival in the US.

The 10 Importer Data Elements

• 1. Seller (or owner): Name and address of the foreign entity that sold the goods.
• 2. Buyer (or owner): Name and address of the US entity purchasing the goods.
• 3. Importer of record number: Your IRS EIN or CBP assigned importer number.
• 4. Consignee number: The IRS EIN of the party receiving the goods in the US.
• 5. Manufacturer (or supplier): Name and address of the entity that manufactured the goods.
• 6. Ship-to party: Name and address of the first delivery location in the US.
• 7. Country of origin: Where the goods were manufactured (not shipped from).
• 8. HTS number: The 6-digit HTS classification of the goods (can be updated to 10 digits later).
• 9. Container stuffing location: Address where the container was loaded with cargo.
• 10. Consolidator (stuffer): Name and address of the party that stuffed the container.

The 2 Carrier Data Elements

The ocean carrier provides two additional data elements: the vessel stow plan (showing the location of all containers on the vessel) and the container status messages (tracking the container through the transportation chain). These are filed separately by the carrier, not by the importer, but any delays in carrier data can affect your shipment's risk score.

Step-by-Step Filing Process

1. Step 1: Gather all 10 data elements from your purchase order, commercial invoice, booking confirmation, and supplier information.
2. Step 2: Identify your ISF filing agent — typically your customs broker or freight forwarder.
3. Step 3: Transmit the ISF data to your filing agent at least 72 hours before estimated vessel loading (to provide buffer time).
4. Step 4: Your agent files the ISF electronically through the Automated Broker Interface (ABI) or ACE.
5. Step 5: CBP processes the ISF and returns a confirmation with an ISF transaction number.
6. Step 6: If CBP identifies issues, they may issue a 'do not load' hold or request additional information.
7. Step 7: Update the ISF with any changes (HTS codes, ship-to party) before 24 hours prior to US arrival.
8. Step 8: After vessel arrival, the ISF is matched to the customs entry for release.

ISF Flexibility and Updates

CBP provides some flexibility in ISF filing. Four of the 10 data elements can be filed with 'flexible' responses initially and updated later: manufacturer, ship-to party, country of origin, and HTS number. The initial filing can use reasonable estimates for these fields, but they must be updated to final, accurate information no later than 24 hours before the vessel arrives in the US. All other data elements must be accurate at the time of initial filing.

Common ISF Filing Mistakes

• Filing late: The 24-hour rule is from vessel loading, not US arrival. Know when your vessel loads.
• Incorrect manufacturer: Using the trading company instead of the actual factory that produced the goods.
• Wrong country of origin: Must be the country of manufacture, not the country of export.
• Not updating flexible fields: Initial estimates must be updated before arrival or penalties apply.
• One ISF for multiple containers: Each bill of lading requires its own ISF transaction.
• Not filing for low-value shipments: ISF has no de minimis exemption — even $100 shipments require filing.
• Using HTS 6-digit only: While acceptable initially, failure to update to 10 digits before arrival triggers penalties.

ISF Best Practices

• Build ISF data collection into your purchase order process — request manufacturer addresses and container stuffing locations upfront.
• File early — do not wait until the deadline. Filing 5-7 days before loading gives you buffer for corrections.
• Maintain a database of supplier information (manufacturer addresses, factory IDs) to speed up filing.
• Automate ISF filing through integration between your ERP/TMS and your broker's ABI system.
• Track ISF status and confirmation numbers for every shipment.
• Review ISF penalty notices promptly — you have 60 days to respond or mitigate.

“The ISF is not just a compliance requirement — it is your first touchpoint with CBP for every ocean shipment. A clean, accurate, on-time ISF sets the tone for a smooth clearance. A late or inaccurate ISF raises red flags before your goods even arrive.”

— Camtom Team