What Is ISF and How Does It Work
Importer Security Filing (ISF) is a U.S. Customs requirement for all ocean cargo entering the United States. It is often referred to as the ‘10+2 rule,’ which combines importer and carrier data to provide Customs with an early view of the shipment. Together, these details give Customs a complete picture of the shipment before it leaves a foreign port.
The filing must be sent electronically at least 24 hours before cargo is loaded on the vessel. Importers or their agents provide information such as shipper, buyer, and manufacturer details. Carriers add the vessel stow plan and container status messages. U.S. Customs and Border Protection (CBP) then uses this data to review risks and clear the shipment for loading.
The process is designed to strengthen supply chain security and reduce delays at U.S. ports. Filing correctly and on time means Customs has the data needed to identify threats while allowing legitimate cargo to move without disruption.
Importer Security Filing Responsibilities
Filing an Importer Security Filing is not handled by a single party. Several players share responsibility, but the importer of record is always legally accountable.
Importer of Record
The importer is the main party responsible for accuracy. They must collect all required data, confirm it is correct, and make sure it is filed before the shipment departs. Even if a broker or forwarder submits the filing, the importer remains legally responsible.
Carrier
The carrier provides the two ‘plus’ elements: the vessel stow plan and container status messages.
Freight Forwarder or Customs Broker
Forwarders and brokers often prepare and transmit ISF filings on behalf of importers. They coordinate with suppliers, consolidate documents, and reduce the risk of missed deadlines. While they help manage the process, they do not remove the importer’s liability.
Required ISF Data Elements (10+2)
An Importer Security Filing relies on a specific set of details known as the ‘10+2’ elements.
10 Importer Data Elements
- Importer of Record Number – The ID number (IRS, EIN, or CBP-assigned) of the party legally responsible for the goods.
- Seller Name and Address – The exporter or party selling the goods.
- Buyer Name and Address – The importer or consignee purchasing the goods.
- Manufacturer (Supplier) Name and Address – The actual producer or supplier, not a trading company.
- Ship-To Party – The delivery destination in the U.S., which may differ from the importer of record.
- Container Stuffing Location – The place where the goods were loaded into the container.
- Consolidator Name and Address – The party responsible for consolidating or stuffing cargo, common in LCL shipments.
- Commodity HTSUS Number – The 6-digit tariff classification code for the goods.
- Country of Origin – Where the goods were manufactured or produced.
- Booking Party – The entity that booked the cargo with the carrier.
2 Carrier Elements
- Vessel Stow Plan – Shows how and where containers are placed on the vessel.
- Container Status Messages (CSMs) – Track container movements and status updates.
Common Filing Mistakes and How to Fix Them
One of the most common errors is late submission. If the ISF is filed after the vessel has loaded, Customs may reject it. Importers can avoid this by setting internal cut-off times at least two days before the carrier’s deadline to allow a buffer.
Another frequent issue is incorrect tariff codes. Using the wrong HTSUS number can cause clearance delays. The solution is to confirm the correct classification with suppliers or a licensed customs broker before the filing is made.
Details such as the stuffing location and ship-to party are also often overlooked. Leaving these blank or using outdated consignee addresses makes the filing incomplete. These details should always be verified with consolidators, packing houses, and buyers before transmission.
A further mistake is failing to amend the filing when errors are found. Customs allows updates until cargo arrival, so any changes such as a new HTS code or updated consignee details should be filed immediately to keep the record accurate.
ISF Penalties and How to Avoid Them
The most common penalty for ISF violations is a liquidated damages fine of up to USD $5,000 per filing. Customs can issue this fine for late or inaccurate submissions. Each shipment is treated separately, so repeat mistakes can multiply quickly.
Customs may also place a cargo hold on containers linked to faulty filings. This can lead to storage charges at the terminal, missed delivery windows, and increased transport costs. In some cases, shipments are flagged for intensive inspection.
Avoiding these penalties starts with accurate data collection. Importers should use checklists, filing reminders, and strong communication with suppliers and brokers to prevent errors. Records of each filing should be kept to create a reliable audit trail in case Customs asks for proof.
ISF Bond Requirement
Every ISF filing must be backed by a bond. This is a guarantee to U.S. Customs that the importer will follow ISF rules and pay any penalties if they fail to comply. If no bond is in place, the shipment will not be released.
A single-entry bond covers one shipment only. It is best for companies that import infrequently. For example, a small furniture retailer bringing in one container from Vietnam each year would use a single-entry bond. It avoids paying for an annual bond they do not need.
A continuous bond covers all ISF filings and customs entries for a year. It is suited to companies with regular imports. For instance, an electronics distributor moving containers from China every month would save money and time with a continuous bond, since they don’t need to buy a new bond for each shipment.
Choosing the right bond depends on import frequency and shipment value. A broker can calculate which option provides the best coverage at the lowest cost.
Special ISF Scenarios
Not every shipment follows the standard ISF-10 rule. Some types of cargo require different filings.
ISF-5 Filings
ISF-5 is used when goods are not formally entering the U.S. For example, a container of textiles from India moving through Los Angeles to Mexico would require ISF-5. The carrier or authorized agent files limited details such as the bill of lading number, shipper, consignee, and cargo description. This gives Customs visibility, even though the goods are only passing through.
Vehicle Imports
Vehicles shipped by ocean must include extra data. The Vehicle Identification Number (VIN) must be reported correctly, or clearance will be delayed. The correct HTSUS code for the vehicle must also be used to calculate duties. For example, a car imported from Japan must have its VIN and classification code aligned across the ISF, bill of lading, and customs entry, or it will be flagged for inspection.
ISF Filing Tips for Small and Medium Importers
Smaller importers often have fewer resources, but compliance is still mandatory. These tips help keep filings accurate and on time:
- Start early – Collect shipment details as soon as the booking is made to avoid last-minute data gaps.
- Use a checklist – Track each of the 10+2 elements so nothing is missed before submission.
- Confirm tariff codes – Verify HTSUS numbers with suppliers or a broker to prevent clearance delays.
- Stay in contact – Keep steady communication with forwarders, carriers, and suppliers for updates.
- Consider low-cost services – Online ISF filing portals or flat-fee broker services can save money for small volumes.
- Keep records – Store all filings and amendments in case Customs asks for proof later.
Create Your ISF on IncoDocs
Managing Importer Security Filings can feel complex, but the process becomes much easier when you have the right tools. With a free IncoDocs account, you can create an ISF document online in minutes, store shipment details securely, and share them with your broker or forwarder. Everything stays in one place, so you reduce errors and keep your filings compliant.
