ISF Filing Requirements: The Complete Guide

An Importer Security Filing (ISF) is a mandatory electronic submission that U.S. importers must send to CBP at least 24 hours before ocean cargo is loaded at a foreign port. Missing this filing — or getting key data wrong — can result in penalties up to $5,000 per shipment and cargo holds that delay your goods for days.

If you move goods into the United States by ocean vessel, ISF compliance is not optional. This guide explains exactly what you need to file, when to file it, how the process works, and what mistakes to avoid.

What Is an Importer Security Filing (ISF)?

Importer Security Filing (ISF): A mandatory pre-shipment data submission, governed by 19 CFR Part 149, that requires importers to electronically transmit specific cargo and supply chain information to U.S. Customs and Border Protection before ocean freight is loaded aboard a vessel bound for the United States.

CBP introduced the ISF program — formally known as the “10+2” rule — in January 2009 under the Security and Accountability for Every Port Act of 2006 (SAFE Port Act). The program was fully enforced beginning July 9, 2013.

The name “10+2” reflects the structure of the filing:

• 10 data elements from the importer or their agent
• 2 data elements from the ocean carrier

The goal is risk assessment. CBP uses ISF data to identify high-risk cargo before it’s loaded at a foreign port — far in advance of arrival at a U.S. seaport. According to CBP, the agency processes more than 11 million ocean containers arriving in the U.S. annually. ISF gives them the advance intelligence to target inspections efficiently.

ISF applies only to ocean freight. Air freight, truck crossings at land borders, and rail shipments operate under separate advance cargo reporting requirements and are not covered by the ISF rule.

The 10 Importer Data Elements + 2 Carrier Elements

Not all ISF filings are identical. CBP distinguishes between two ISF types based on the shipment:

The 10 Importer Data Elements (ISF-10)

For a standard ISF-10 filing, you must provide:

1. Seller name and address — the party selling the goods to the importer
2. Buyer name and address — typically the U.S. importer of record
3. Importer of record number — IRS EIN, SSN, or CBP-assigned number
4. Consignee number — IRS EIN or SSN of the party receiving the goods in the U.S.
5. Manufacturer (or supplier) name and address — the factory or supplier producing the goods
6. Ship-to party name and address — the first U.S. destination after arrival
7. Country of origin — where the goods were manufactured or substantially transformed
8. Harmonized Tariff Schedule (HTS) code — minimum 6 digits at time of filing
9. Container stuffing location — address where goods were loaded into the container
10. Consolidator name and address — party responsible for stuffing the container

The 2 Carrier Data Elements

The ocean carrier — not the importer — is responsible for filing:

1. Vessel stow plan — where containers are physically located on the vessel
2. Container status messages — container movement events throughout transit

How the ISF Filing Process Works

The ISF process follows a defined sequence from purchase order to cargo arrival. Here is the standard workflow:

Step 1 — Gather shipping documents Once goods are ready for export, your overseas supplier or freight agent provides the commercial invoice, packing list, and booking confirmation. These documents contain the data you need for the ISF.

Step 2 — Transmit ISF data to your broker or file directly You (or your licensed customs broker) must transmit the 10 importer data elements to CBP. Most importers work through a licensed broker who files via CBP’s Automated Broker Interface (ABI) system. Direct filers can use the ACE Portal at cbp.gov.

Step 3 — Meet the 24-hour deadline The ISF must be submitted at least 24 hours before loading at the foreign port of lading — not 24 hours before arrival at the U.S. port. This is a critical distinction. A shipment loading in Shanghai that takes 18 days to reach Los Angeles still requires ISF submission 24 hours before the Shanghai loading date.

Step 4 — Receive CBP acceptance or hold CBP’s automated system reviews the filing and assigns a risk score. If the filing is accepted, cargo can load. If CBP identifies a risk or a required data element is missing, they may issue a “do not load” (DNL) message to the carrier.

Step 5 — Amend if necessary Some data elements — specifically container stuffing location and consolidator information — are permitted to be filed as late as 24 hours after vessel departure, provided the initial ISF was submitted on time with all other elements. All amendments must be submitted before arrival at the first U.S. port.

Step 6 — CBP matches ISF to entry at arrival When the vessel arrives, CBP reconciles the ISF data against the vessel manifest, the entry summary, and any other advance data. Discrepancies can trigger additional scrutiny.

The Regulatory Framework

ISF requirements are codified under 19 CFR Part 149 — the Importer Security Filing regulations promulgated by CBP. The underlying legal authority comes from:

• 19 USC 1431(a) — requires vessel manifests and advance cargo information
• Section 203 of the SAFE Port Act of 2006 — mandated the 10+2 rule
• 19 CFR Part 149 — the specific ISF regulations, including definitions, timing requirements, and penalty provisions

Penalties for non-compliance are issued as liquidated damages under the bond the importer holds with CBP. Under 19 CFR Part 149.7, CBP can assess up to $5,000 per violation. Each shipment with a non-compliant ISF is a separate violation. An importer who ships 20 containers per month without filing ISF is potentially exposed to $100,000 in monthly liquidated damages.

CBP published its ISF enforcement policy and mitigation guidelines through a series of trade notices. Penalties can sometimes be mitigated — reduced based on the importer’s history and the nature of the violation — but mitigation is not guaranteed, and the process is burdensome.

For authoritative regulatory text, CBP maintains the official ISF program information at cbp.gov. HTS code lookup for element #8 is available at hts.usitc.gov.

Real-World Scenarios: ISF in Practice

Understanding how ISF requirements play out in actual import operations helps clarify where compliance breaks down.

Scenario 1: The First-Time Amazon FBA Importer

A seller sourcing private-label products from a factory in Guangzhou, China, arranges ocean freight through a freight forwarder. The goods are valued at $8,000 — well above the $800 de minimis threshold. The seller doesn’t know ISF exists and doesn’t retain a customs broker.

The cargo loads without an ISF on file. When the container arrives at the Port of Long Beach, CBP flags it for an intensive exam. The exam takes four days, costs $1,800 in port and exam fees, and CBP issues a $5,000 liquidated damages notice. The seller’s total compliance failure costs more than the product margin on the shipment.

Working with a CBP-licensed customs broker would have prevented all of it.

Scenario 2: Incomplete Manufacturer Data

A mid-size apparel importer files ISF on time, but their broker lists the trading company — not the factory — as the manufacturer. The goods were produced at a factory in Vietnam that is subject to additional CBP scrutiny.

CBP matches the ISF manufacturer information against known supply chain data and flags the discrepancy. The cargo is held for secondary review. The importer amends the ISF, but the correction after arrival does not prevent the hold. Clearance is delayed by three days, and CBP issues a penalty notice.

Scenario 3: Correct Filing, Smooth Clearance

A pharmaceutical supply company importing active pharmaceutical ingredients (API) from India retains a licensed broker who specializes in pharmaceutical imports. See brokers by specialty for examples of this type of specialist.

The broker collects the commercial invoice, packing list, and manufacturer information five days before the estimated loading date. ISF is filed six days before loading, with accurate HTS codes at the 6-digit level. All 10 data elements are complete. Cargo loads on schedule, CBP accepts the filing, and the shipment clears customs without examination.

Common ISF Mistakes (and How to Avoid Them)

Mistake 1: Confusing the 24-hour deadline

The deadline is 24 hours before loading at the foreign port — not 24 hours before the ship arrives in the U.S. An importer who waits until a vessel departs Shanghai is already too late. Build a process that triggers ISF filing as soon as cargo is ready for export.

Mistake 2: Using vague or incorrect HTS codes

Some importers enter a rough 4- or 6-digit HTS code just to satisfy the filing requirement. CBP requires a minimum of 6 digits at filing, but the code must be accurate — it feeds risk modeling and, later, duty assessment. Wrong codes on ISF that conflict with the entry summary draw scrutiny. Use hts.usitc.gov to verify codes before filing.

Mistake 3: Listing the wrong manufacturer

The ISF manufacturer element should reflect the entity that actually produced the goods — the factory — not the trading company, buying agent, or exporter. This distinction matters especially for goods from countries with active antidumping or countervailing duty orders. Check the AD/CVD orders database if you’re importing goods where this risk exists.

Mistake 4: Not filing at all for LCL (less-than-container-load) shipments

ISF applies to LCL shipments as much as it does to full container loads. Some importers assume small shipments are exempt. They are not. Every ocean shipment requiring a formal entry (value over $2,500, or restricted goods regardless of value) needs an ISF.

Mistake 5: Failing to update the ISF after booking changes

If the vessel, port of lading, or container changes after ISF submission, the filing must be amended. Amendments are common in ocean freight — but they require action. Many importers file ISF and assume it’s done, never following up with their broker when logistics details shift.

Tools and Resources for ISF Compliance

Most importers do not file ISF themselves — they authorize a licensed customs broker to file on their behalf. This is standard practice because brokers have direct ABI system access, maintain knowledge of current CBP requirements, and can respond quickly to CBP queries or amendment requests.

If you import via multiple U.S. ports — say, ocean containers arriving at both Los Angeles and New York — consider whether a single national broker or regional specialists better fit your needs. You can browse brokers by U.S. port of entry to identify licensed brokers active at your specific arrival ports, or browse by state to find local coverage.

The National Customs Brokers & Forwarders Association of America (ncbfaa.org) also maintains educational resources on ISF and other trade compliance topics.

Who Should File — and Who Actually Does

Legally, the ISF Importer — the party causing goods to arrive in the U.S. — bears responsibility for the filing. That is almost always the U.S. buyer or consignee, not the foreign seller.

However, the ISF Importer may delegate the filing to a licensed customs broker or freight forwarder through a power of attorney. When they do, the agent files on behalf of the importer, but the importer retains legal liability for the accuracy of the data. If your broker files an ISF with wrong information you provided, the penalty accrues to you, not the broker.

This makes data quality a shared responsibility. A good broker will ask the right questions and flag inconsistencies,