What is ISF 10+2? Complete Guide to Importer Security Filing for US Imports

What is ISF 10+2? The Complete Guide to Importer Security Filing

The Importer Security Filing (ISF), universally known as “10+2,” is a mandatory U.S. Customs and Border Protection (CBP) requirement that governs every ocean cargo shipment entering the United States. Enacted under the SAFE Port Act of 2006 and enforced beginning January 26, 2009, ISF 10+2 compels importers to electronically transmit 10 specific data elements to CBP no later than 24 hours before the cargo is loaded onto a vessel at the origin port. The ocean carrier contributes 2 additional data elements — a vessel stow plan and container status messages — giving the regulation its “10+2” name.

ISF is not a formality. It is CBP’s primary advance intelligence tool for identifying high-risk shipments before they ever leave a foreign port. In FY2024, CBP processed over 10 million ISF filings and levied millions of dollars in penalties against importers who filed late, filed inaccurately, or failed to file at all. Understanding ISF 10+2 in full — what it is, who owes it, every data element, the penalty structure, and how it connects to broader trade compliance — is non-negotiable for any serious U.S. importer.

This guide covers everything: the legislative foundation, all 10 data elements with examples, the 2 carrier elements, filing deadlines, CBP’s enforcement process, the connection to Section 301 tariffs, HTS code accuracy requirements, customs bonds, importer of record obligations, and how ISF interacts with sister programs like AMS (Automated Manifest System) and ACAS (Air Cargo Advance Screening).

Legislative Background: The SAFE Port Act and CBP’s Risk-Based Strategy

The Security and Accountability For Every (SAFE) Port Act of 2006 (Public Law 109-347) authorized CBP to collect advance cargo data for all inbound ocean shipments. The Act was a direct legislative response to post-9/11 vulnerabilities in global supply chains. Prior to ISF, CBP received cargo information only after a vessel departed — leaving little time to identify weapons of mass destruction, contraband, or other threats hidden inside the 700+ million containers that move through U.S. ports each year.

The SAFE Port Act mandated that CBP develop a system to receive importer-specific data — separate from carrier-provided manifest data — at least 24 hours before loading. This became the Importer Security Filing rule (19 CFR Parts 4, 12, 18, 101, 103, 113, 122, 123, 141, 143, 149, and 192), finalized in November 2008 and effective January 26, 2009.

ISF works alongside the Automated Manifest System (AMS), which requires carriers to submit advance electronic cargo manifests 24 hours before loading (the “24-Hour Rule”). Together, ISF + AMS give CBP two independent data streams to run risk-scoring algorithms. CBP’s Automated Targeting System (ATS) cross-references both filings to flag shipments for examination, holds, or seizure before they approach U.S. shores.

Who Must File ISF 10+2?

ISF 10+2 applies to:

All ocean freight shipments arriving in the United States by vessel, regardless of value, weight, or country of origin
All importers of record — U.S. companies, foreign sellers shipping DDP, Amazon FBA sellers, and individual consumers importing personal goods by ocean
Informal entries and formal entries alike — there is no de minimis exemption for ISF

ISF does NOT apply to:

Air freight shipments (covered instead by ACAS — Air Cargo Advance Screening)
Truck and rail entries from Canada and Mexico
Bulk cargo (petroleum, grain, ore) as defined under 19 CFR 149.2(c)
Break-bulk cargo specifically exempted by CBP

The importer of record is legally liable for ISF compliance even when they delegate the filing to a licensed customs broker or freight forwarder. Delegation does not transfer liability — it transfers the task. This distinction matters enormously when CBP assesses penalties.

For companies importing from China, ExFreight’s China-to-USA ocean freight service includes ISF filing as a standard component of every booking — no extra fees, no manual reminders required.

The 10 Importer Data Elements: Complete Reference Table

The following table defines all 10 importer-provided data elements required under 19 CFR 149.3, with the level of accuracy CBP expects:

#	Data Element	Description & CBP Requirements	Common Errors
1	Manufacturer (or Supplier) Name & Address	The actual factory or entity that produced the goods. Must be the physical manufacturer — not a trading company intermediary. If a trading company is used and the true factory is unknown, the trading company may be listed, but CBP increasingly scrutinizes this.	Listing the trading company instead of the actual factory; using a PO Box
2	Seller Name & Address	The entity selling the goods to the U.S. buyer. May be a trading company, distributor, or the manufacturer itself. Must match the commercial invoice.	Confusing seller with the manufacturer; mismatched invoice addresses
3	Buyer Name & Address	The U.S. purchaser of the goods as identified in the purchase order or commercial invoice. This is typically the U.S. importer of record.	Using a parent company’s address instead of the actual buying entity
4	Ship-To Name & Address	The final U.S. delivery address — where goods will ultimately be delivered after customs clearance. For Amazon FBA shipments, this is the FBA warehouse address, not Amazon’s corporate headquarters.	Listing the port of entry instead of the final destination; wrong FBA warehouse address
5	Container Stuffing Location	The physical address where goods were loaded into the container. If multiple stuffing locations are used (LCL consolidation), all locations must be listed. This must be a real street address — not “various” or a city name.	Listing a city without a street address; omitting for LCL cargo
6	Consolidator (Stuffer) Name & Address	The party who physically loaded the goods into the container. May be the manufacturer, a third-party logistics (3PL) warehouse, or a freight consolidator. If the manufacturer stuffed the container, the manufacturer is listed again here.	Leaving blank when the manufacturer is the stuffer; confusing with NVOCC or freight forwarder
7	Importer of Record Number	The IRS Employer Identification Number (EIN), Social Security Number (for individuals), or CBP-assigned number of the party who will be the importer of record on the CBP Form 3461 entry. This must be a valid, active number.	Using the freight forwarder’s EIN; using an inactive or incorrect EIN
8	Consignee Number	The IRS EIN or CBP number of the ultimate U.S. consignee — the party who will receive the goods after customs clearance. In most standard imports, this is the same as the importer of record number. They may differ in certain trade transactions.	Assuming it always equals the importer of record number without confirming
9	Country of Origin	The country where the goods were manufactured or substantially transformed. This is NOT the country of export. Goods assembled in Vietnam from Chinese components may require a country-of-origin analysis. Country of origin determines which tariff rates apply, including Section 301 duties.	Listing China as origin for goods assembled in Vietnam; confusing origin with export country
10	HTS Number (Harmonized Tariff Schedule)	The Harmonized Tariff Schedule of the United States (HTSUS) classification number, minimum 6 digits (CBP recommends 10-digit specificity). The HTS code determines the duty rate and any applicable trade remedy (Section 301, antidumping/countervailing duties). The HTS number on the ISF must match the formal entry — mismatches trigger flags.	Using a 6-digit HS code instead of the 10-digit HTSUS; wrong classification; code not matching the entry

The 2 Carrier Data Elements

Ocean carriers (or their agents) are responsible for two additional data elements under 19 CFR 149.4:

Vessel Stow Plan — A complete electronic list of all containers on the vessel, showing their physical stow location (bay/row/tier). Must be submitted within 48 hours after the vessel departs its last foreign port, or for voyages under 48 hours, before arrival. The stow plan allows CBP to locate specific containers for targeted inspections without unloading the entire vessel.
Container Status Messages (CSMs) — Real-time electronic messages reporting key container events: gate-in at the origin terminal, loading onto the vessel, vessel arrival, and discharge. These messages allow CBP to track container movement and flag anomalies.

Carriers who fail to submit vessel stow plans or container status messages face their own penalty exposure — separate from importer penalties. This is why the program is called “10+2” and not simply “ISF-10.”

ISF Filing Deadlines: The 24-Hour Rule Explained

The ISF must be filed no later than 24 hours before the cargo is loaded onto the vessel at the foreign port of lading. This is a critical distinction from the carrier 24-Hour Rule, which also runs from vessel departure but measures different events:

ISF deadline: 24 hours before vessel loading at the origin port
AMS (carrier manifest) deadline: 24 hours before vessel loading at the origin port
Not 24 hours before arrival in the United States

A common misconception: if a ship takes 14–18 days to sail from Shanghai to Los Angeles, some importers assume they have until 24 hours before arrival to file ISF. This is wrong. The 24-hour clock starts before the ship leaves Shanghai, not before it reaches LA. By the time the vessel is mid-Pacific, your ISF filing window has long closed.

For LCL (Less than Container Load) shipments, the ISF deadline is actually stricter in practice — because LCL cargo is consolidated days before the mother vessel loads. Importers must provide ISF data to their freight forwarder 48–72 hours before the CFS (Container Freight Station) cutoff to ensure timely filing.

Understanding shipping terms is directly relevant here: under FOB (Free On Board) terms, risk and responsibility transfer when goods are loaded onto the vessel — the same moment the ISF deadline is triggered.

ISF Penalties: The Real Numbers

CBP enforces ISF under its liquidated damages authority. The penalty structure under 19 CFR 149.6 and CBP’s penalty mitigation guidelines is:

Late filing: Up to $5,000 per violation per shipment
Inaccurate filing: Up to $5,000 per violation per shipment
Failure to file: Up to $10,000 per violation per shipment
Repeat violations / aggravated cases: Liquidated damages up to $50,000 per violation
Do Not Load (DNL) orders: CBP can instruct the carrier not to load the container if ISF is not filed; this results in missed vessel bookings and potentially weeks of delay
Intensive Examinations (CET/VACIS/X-ray): Late or inaccurate ISF filings trigger elevated exam rates, adding $800–$3,500 per container in exam fees plus 5–15 day delays at port

In practice, CBP has increasingly moved toward penalty enforcement rather than warnings for ISF violations, particularly since 2020. Importers with a history of late filing can expect penalty notices rather than courtesy calls. CBP’s Penalty Policy does provide a mitigation schedule for first-time, non-willful violations — penalties may be mitigated to 50% of the claimed amount if the importer responds promptly and demonstrates corrective action.

The financial exposure from ISF penalties can compound quickly. An importer running 20 ocean shipments per month who consistently files ISF 2 hours late faces theoretical exposure of $100,000/month — easily exceeding the freight cost of the goods being imported.

ISF and the Customs Bond Requirement

ISF filers are required to have a valid U.S. Customs bond on file with CBP. The ISF bond is a separate instrument from the entry bond (CF-301), though many importers use a single continuous bond that covers both ISF and formal entry obligations.

There are two types of customs bonds relevant to ISF:

Single Transaction ISF Bond: Covers one ISF filing. Used by infrequent importers. Typically costs $30–$75 per shipment.
Continuous ISF Bond: Covers all ISF filings for a 12-month period. Required when importing 3+ times per year. Minimum bond amount is $50,000 (10x the estimated duties/fees, subject to CBP minimums). Annual premium typically runs $500–$800 for standard importers.

Critically: if CBP assesses ISF liquidated damages, CBP will make a claim against the surety company that issued the customs bond — not just send a bill to the importer. The surety pays, then seeks reimbursement from the importer. This creates a paper trail that can affect future bond renewals and premiums.

The ISF Process: Step-by-Step Timeline

Understanding the sequence of events helps importers and freight forwarders coordinate ISF compliance without scrambling at the last minute:

Purchase Order Confirmed (T-21+ days before vessel departure) — Importer confirms order with Chinese supplier. Gather: manufacturer name/address, seller name/address, HTS code, country of origin.
Booking Confirmed (T-14 days) — Ocean carrier or NVOCC assigns a booking number. Freight forwarder opens the shipment file. ExFreight customers receive an ISF data collection request at this stage.
CFS Cutoff / Factory Stuffing (T-7 to T-4 days) — For LCL: cargo arrives at the Container Freight Station for consolidation. For FCL: factory stuffs the container and provides container number and seal number. Container stuffing location (Element #5) and consolidator info (Element #6) are now confirmed.
ISF Filing Deadline (T-24 hours before loading) — Customs broker or freight forwarder files ISF electronically via CBP’s Automated Broker Interface (ABI). CBP assigns a transaction number (ACE reference). ISF status becomes “Accepted.”
Vessel Loading (T-0) — Carrier loads the container. Vessel stow plan and container status messages begin transmitting to CBP.
Vessel Departure — CBP’s Automated Targeting System runs risk scoring against the ISF and AMS manifest data. High-risk shipments are flagged for examination or Do Not Unload holds.
Pre-Arrival (3–5 days before U.S. arrival) — Customs broker prepares and files the formal entry (CBP Form 3461 / 7501). The importer of record number on the entry must match Element #7 of the ISF.
U.S. Port Arrival & Customs Clearance — CBP releases the shipment (or issues an exam order). ISF is “matched” to the entry in CBP’s ACE system. Unmatched ISFs generate compliance flags.
Cargo Release & Delivery — Goods are released to the importer. Free time at the terminal begins running — importers must pick up cargo before demurrage charges accrue.

ISF and HTS Codes: Why Classification Accuracy is Critical

Element #10 — the Harmonized Tariff Schedule (HTS) code — is arguably the highest-stakes data field in the ISF. The HTS code:

Determines the Section 301 tariff rate applicable to Chinese-origin goods (0%, 7.5%, 25%, or potentially higher under recent executive actions)
Triggers antidumping (ADD) and countervailing duty (CVD) assessment if the product falls under an active trade remedy order
Drives CBP’s risk-targeting algorithms — misclassified goods are a red flag for intentional evasion
Must match the HTS code used on the formal entry (CBP Form 7501) — a mismatch between the ISF HTS and the entry HTS creates a discrepancy that CBP auditors investigate

Under the Section 301 tariffs on Chinese goods, the HTS code is the single most consequential classification decision an importer makes. Goods classified under List 1 carry 25% additional duties. List 4A goods carry 7.5%. Goods that were reclassified to avoid Section 301 have been the subject of major CBP enforcement actions, including penalty cases under 19 USC 1592 (fraud, gross negligence, negligence) carrying penalties up to 4x the unpaid duties.

ISF is the first formal statement of HTS classification to CBP. When the ISF HTS code later disagrees with the formal entry, CBP interprets this as either negligence (unintentional mismatch) or a potential indicator of fraud. The safest practice: use the same 10-digit HTSUS number in both the ISF and the entry, confirmed by a licensed customs broker before the ISF is filed.

ISF for Amazon FBA Sellers

Amazon FBA sellers importing ocean freight from China face a specific set of ISF obligations that Amazon does not handle on their behalf. Amazon is not your customs broker. Amazon is not your importer of record. Amazon does not file ISF for you.

Key ISF requirements for Amazon FBA importers:

Importer of Record: The FBA seller is the importer of record, not Amazon. Your IRS EIN must appear in ISF Element #7 and on the CBP entry.
Ship-To Address: Element #4 must list the specific Amazon FBA fulfillment center address assigned in your FBA shipment plan — e.g., “3501 Scarlet Oak Blvd, St. Louis, MO 63122.” Do not list Amazon’s Seattle headquarters.
Customs Bond: FBA sellers must maintain their own customs bond — Amazon’s bond does not cover your imports.
FBA Shipment Plan Changes: Amazon sometimes changes the assigned FBA warehouse after a seller creates a shipment plan. If this happens after ISF is filed, the importer must amend Element #4 before vessel loading to avoid an inaccurate filing penalty.

FBA sellers sourcing from China should work with a freight forwarder experienced in FBA imports — ISF timing, correct FBA address routing, and customs bond management are all interconnected. ExFreight’s Amazon FBA freight service handles all of these elements as part of a coordinated booking process.

ISF vs. AMS vs. ACAS: Understanding the Full Advance Data Ecosystem

ISF is one of three major advance cargo data programs CBP administers. Understanding how they differ prevents confusion when your freight forwarder mentions any of the three:

Program	Full Name	Mode	Who Files	Deadline
ISF 10+2	Importer Security Filing	Ocean only	Importer (via broker/forwarder)	24 hrs before vessel loading
AMS	Automated Manifest System	Ocean, Air, Truck, Rail	Carrier or NVOCC	24 hrs before vessel loading (ocean)
ACAS	Air Cargo Advance Screening	Air only	Airline / freight forwarder	Before wheels up at origin

When choosing between air freight vs. ocean freight, it’s worth noting that air shipments avoid ISF but are subject to ACAS, which has its own advance data requirements. Neither is “easier” from a compliance standpoint — they simply involve different regulatory frameworks.

ISF Amendments: When and How to Update a Filed ISF

Circumstances change after an ISF is filed. CBP permits ISF amendments, but the timing determines whether a penalty applies:

Amendments before vessel loading: Permitted and encouraged. No penalty as long as the amendment is submitted before the ship loads. This covers HTS changes, address corrections, and supplier changes.
Amendments after vessel loading but before U.S. arrival: Generally accepted by CBP, but may attract scrutiny if the change involves high-risk elements (HTS code, country of origin, manufacturer). CBP reserves the right to assess a penalty.
Amendments after cargo arrives: Very limited circumstances. CBP typically treats post-arrival ISF changes as inaccurate filings subject to penalty.

Best practice: treat your ISF as a living document during the booking phase and finalize all data elements before the vessel cutoff. Lock in the HTS code and country of origin before the ISF is filed — not after.

Section 301 Tariffs and ISF Compliance Strategy

The USTR Section 301 tariffs on Chinese goods (initiated in 2018 and expanded through 2024–2025 executive actions) have made ISF accuracy more consequential than ever. Under Section 301:

The HTS code in the ISF is CBP’s first signal of which tariff list applies to a shipment
Importers who misclassify goods to avoid Section 301 duties face penalties under 19 USC 1592 — up to 4x the unpaid duties for negligent violations, and up to 4x the domestic value for fraud
Country of origin in Element #9 directly determines whether Section 301 applies — goods genuinely manufactured in Vietnam, Mexico, or other non-China countries are exempt, but CBP heavily scrutinizes origin claims where Chinese inputs constitute a majority of the product’s value
CBP’s Enforce and Protect Act (EAPA) investigations increasingly start with ISF data cross-referenced against entry data — discrepancies trigger investigation referrals

Working with an experienced freight forwarder like ExFreight, who understands the intersection of ISF compliance and Section 301 tariff strategy, is essential for importers sourcing from China or diversifying supply chains to tariff-neutral countries.

ExFreight’s ISF Filing Process

For all ocean freight shipments handled by ExFreight, ISF filing is integrated into the standard booking workflow at no additional charge:

Data collection at booking: Our system prompts for all 10 ISF elements when you create a shipment
Classification review: Our customs team verifies the HTS code against CBP’s CROSS database and the Section 301 tariff lists
Filing within 2 business hours: ISF is transmitted via our licensed ABI connection to CBP’s ACE portal
ACE confirmation: You receive the CBP transaction number as confirmation of accepted filing
Amendment management: If supplier details change before loading, we amend the ISF automatically
Entry matching: We cross-reference the ISF data when preparing the formal customs entry to ensure zero discrepancies

For China-to-USA ocean freight, ExFreight’s all-inclusive quoting means ISF is never an unexpected line item on your invoice.

Frequently Asked Questions About ISF 10+2

1. Does ISF apply to small parcel shipments or express courier (DHL, FedEx, UPS)?

No. ISF applies exclusively to ocean freight arriving by vessel. Small parcels and express courier shipments arrive by air and are subject to ACAS (Air Cargo Advance Screening) administered by the airline, not the importer. Express shipments may also qualify for Section 321 de minimis clearance if the declared value is under $800 — but this is an entry exemption, not an ISF exemption, since ISF does not apply to air in any case.

2. My Chinese supplier says they will handle ISF. Is that allowed?

In some cases, a foreign supplier shipping under DDP (Delivered Duty Paid) terms can act as the U.S. importer of record and file ISF — but this is uncommon and legally complex. For standard FOB and CIF shipments where the U.S. buyer is the importer of record, the U.S. buyer (or their customs broker) must file ISF. A Chinese supplier cannot file ISF using your EIN — that would constitute unauthorized use of your tax ID. Always confirm who holds the importer of record role before delegating ISF responsibility.

3. What happens if the vessel loading date changes and my ISF was filed based on the original schedule?

If the vessel is delayed and the original ISF was filed based on the originally scheduled loading date, the ISF remains valid — it does not expire or need to be refiled simply because of a schedule change. The ISF is tied to the shipment, not to a specific sailing date. However, if the routing changes (different vessel, different port of lading), the ISF must be amended to reflect the new vessel and voyage information.

4. Can I use a 6-digit HS code instead of a 10-digit HTSUS number in the ISF?

CBP technically accepts a minimum of 6 digits for ISF purposes. However, this is strongly discouraged. A 6-digit code is the international HS base code — it does not reflect U.S.-specific subdivisions that determine whether Section 301, antidumping, or countervailing duties apply. Using a 10-digit HTSUS code reduces your risk of an inaccurate filing penalty and ensures the ISF matches your formal entry. Licensed customs brokers always use the full 10-digit code.

5. If my freight forwarder files ISF and makes an error, am I still liable?

Yes. The importer of record is the legally liable party for ISF accuracy regardless of who physically files the document. When you hire a customs broker or freight forwarder to file ISF on your behalf, you are granting them power of attorney to act as your agent — but liability remains with the principal (you). If your freight forwarder files the wrong HTS code, you owe the penalty, not them (though you may have a civil claim against the broker for indemnification if negligence can be proven). This is why reviewing ISF filings — not just approving them blindly — is sound compliance practice.

ISF Best Practices Summary

Start early: Begin collecting ISF data elements the moment a purchase order is confirmed — not when the cargo is ready to ship
Verify HTS codes: Use CBP’s CROSS ruling database and confirm 10-digit HTSUS codes with a licensed broker before filing
Know your country of origin: Especially relevant for goods with Chinese inputs assembled in third countries — origin analysis is a compliance obligation, not a guess
Maintain a continuous customs bond: If you import by ocean more than 3 times per year, a continuous bond is essential and cost-effective
Work with a forwarder that includes ISF: Not all freight forwarders include ISF as a standard service — confirm this before booking
Audit your ISF filings quarterly: Review filed ISFs against your formal entries to catch HTS mismatches, address errors, and importer of record discrepancies before CBP does
Understand demurrage exposure: ISF-triggered exams at port can eat into free time quickly — know your demurrage and detention terms before cargo arrives

ISF 10+2 is one of the most consequential regulatory requirements in U.S. import compliance — and one of the most commonly misunderstood. Getting it right requires accurate data, correct HTS classification, a valid customs bond, and a freight forwarder who treats ISF as a professional obligation rather than an afterthought.

ExFreight handles ISF filing for every ocean shipment we manage — from China-to-USA FCL and LCL to Amazon FBA imports — as part of our standard service. Request a quote today and let our customs team ensure your next shipment arrives compliant, on time, and without penalties.