How US customs clearance works, from arrival to liquidation

Short answer: US customs clearance happens in two stages. First the goods are released: the importer or its customs broker files the entry (CBP Form 3461 or its electronic equivalent) within 15 calendar days of arrival with a bond on file, and U.S. Customs and Border Protection (CBP) releases the cargo or holds it for examination. Then the money is settled: the entry summary (CBP Form 7501) with estimated duties follows within 10 working days, and CBP finalizes the entry at liquidation, which its system schedules 314 days after entry by default.

Most importers see only the first stage, because the truck shows up and the goods go to the warehouse. The second stage is where a wrong HTS code costs money, often months after anyone remembers the shipment. This guide follows one entry from before the ship sails to the end of the protest period, with the regulation behind each step, and marks the points where classification problems come to the surface.

Before arrival: what has to be filed and gathered?

For ocean cargo, the first filing is the Importer Security Filing (ISF), and it is due “no later than 24 hours before the cargo is laden aboard the vessel at the foreign port” (19 CFR 149.2(b)). The ISF importer reports seller, buyer, importer of record number, consignee, manufacturer, ship-to party, country of origin, container stuffing location, consolidator, and the commodity’s HTSUS (US Harmonized Tariff Schedule) number, which “must be provided to the six-digit level” (19 CFR 149.3(a)). Two of those elements, the container stuffing location and the consolidator, may follow later but no later than 24 hours before the vessel arrives in a US port. Air and truck shipments have no ISF.

Before the goods land, the importer of record (the party legally responsible for the entry, its duties and its accuracy) also needs an importer number on file with CBP, a customs bond, and the commercial documents: commercial invoice, packing list, and the bill of lading or air waybill. Goods regulated by another agency need that agency’s data too, such as FDA prior notice for food. Many importers hand the filing to a licensed customs broker, but the broker files on the importer’s behalf; the importer of record keeps responsibility for the classification and value it declares.

Arrival and entry: what does Form 3461 do?

The entry is the filing that asks CBP to release the goods. Under 19 CFR 142.2(a), merchandise “will be entered within 15 calendar days after landing from a vessel, aircraft or vehicle,” or after arrival at the destination port for goods moving in bond. The entry is usually made in ACE (CBP’s Automated Commercial Environment) on the electronic equivalent of CBP Form 3461, and it can be filed before the goods arrive so that release decisions are ready when the cargo is.

No bond, no release. 19 CFR 142.4(a) says merchandise “shall not be released from Customs custody” on a formal entry unless a single entry or continuous bond with the 19 CFR 113.62 conditions has been filed. How large that bond has to be, and why a classification change can make it too small, is the subject of how a customs bond amount is calculated.

The entry type follows the value and the goods. Shipments over $2,500 go on a formal entry. Shipments of $2,500 or less can usually use informal entry (19 CFR 143.21), with exceptions such as articles valued over $250 that are classified in Chapter 99, Subchapters III and IV, where temporary trade measures such as the Section 232 additional duties are listed. Since the de minimis exemption was suspended for all countries in August 2025, low-value goods that used to arrive without an entry need one too; the options are laid out in shipping low-value goods after de minimis.

Release, exams and partner agency review: why do goods get held?

Release is CBP’s decision that the goods can leave its custody. CBP screens the entry and ISF data against its targeting rules and either releases the cargo or orders an examination. Exams range from imaging the container to a full devanning at a centralized examination station (CES), which 19 CFR 118.1 defines as “a privately operated facility, not in the charge of a Customs officer.” The CES bills its users for its services under a fee schedule (19 CFR 118.4), and the goods wait while the exam is scheduled.

Partner government agencies (PGAs) such as FDA, USDA, CPSC and EPA run their own reviews in parallel, and a PGA hold can keep goods at the port after CBP itself has no objection. The HTS number is already doing work here, before anyone has looked at duty: in ACE, many HTS numbers are flagged for particular agencies, so a code in the wrong chapter can either trigger a PGA data requirement the product does not need or skip one it does. A first shipment from a new importer is the most likely to be stopped; the usual causes and fixes are in why CBP holds a first import and how to clear it.

Entry summary and payment: what goes on Form 7501?

The entry summary is the filing that declares classification, value, origin and duty, and pays the estimated duty. 19 CFR 142.12(b) requires it “with estimated duties attached, within 10 working days after the time of entry.” The “time of entry” that starts this clock is defined in 19 CFR 141.68 and depends on how and when the entry was filed, so confirm it with your broker; it is not always the arrival date. Some importers file the entry summary together with the entry, so a single filing does both jobs.

Each line of a 7501 carries a 10-digit HTSUS number, the country of origin, the entered value, the duty rate and amount, any Chapter 99 lines for additional duties (Section 232, Section 301 and others), and fees. The merchandise processing fee is 0.3464% of value within a per-entry minimum and maximum that CBP adjusts each fiscal year, and ocean cargo adds the 0.125% harbor maintenance fee. The field-by-field reading, including how to check the duty math against the codes, is in reading CBP Form 7501 to check classification and duty.

The ISF needs only six digits; the 7501 carries the full 10-digit number. Both should describe the same product, and when the first six digits do not match, the mismatch is visible to anyone who compares the two filings.

After release: what are Forms CF-28 and CF-29?

A Form CF-28 is CBP’s Request for Information. An import specialist reviewing the entry summary asks for something specific: product literature, a breakdown of materials, a sample, proof of origin or valuation documents. 19 CFR 151.11 asks for “prompt” compliance with sample requests and sets no fixed number of days. The reply date therefore comes from CBP, not from the regulation: find it in the request, treat it as firm, answer exactly what was asked with documents, and ask in writing for more time if you need it.

A Form CF-29 is a Notice of Action. It tells the importer that CBP proposes to change the entry, or has changed it, often by moving goods to a different HTS line or adjusting the value. Under 19 CFR 152.2, when CBP believes the entered rate or value is too low and the added duty on the entry exceeds $15, it must notify the importer on Form 29, and liquidation “shall not be withheld for a period of more than 20 days” after the notice is mailed unless CBP sees compelling reasons. A proposed action is the last cheap moment to argue the classification, before liquidation turns it into a bill.

Importers can also fix their own errors before liquidation. A post-summary correction (PSC) can be filed within 300 days of entry and no later than 15 days before the scheduled liquidation date. After liquidation, the routes are a protest or, where a violation is involved, a prior disclosure.

Liquidation and the protest window: when is an entry final?

Liquidation is CBP’s final computation of the duties on an entry. Under 19 USC 1504, an entry not liquidated within one year of entry is deemed liquidated at the rate, value and amount the importer declared, unless CBP extended or suspended liquidation; extensions can run to a four-year limit. In a March 6, 2026 declaration to the Court of International Trade, CBP’s executive director of trade programs stated that ACE “is programmed to automatically liquidate entries 314 days after the date of entry,” unless liquidation is extended or suspended or a CBP user pulls the entry out of the automated run.

Liquidation starts the protest clock. A protest under 19 USC 1514 must be filed within 180 days after liquidation (or after the decision being protested). A classification argument that was not made in the CF-29 stage can still be made in a protest, but by then the higher duty has already been billed. Records for the entry have to be kept for five years from the date of entry in most cases (19 CFR 163.4), so the evidence for the code needs to outlive the protest period by years.

Where do classification errors surface?

A classification error rarely stops a shipment at the dock. It shows up later, at the stage where someone compares the code with the product. The table below maps each stage of clearance to what a wrong HTS code looks like there.

Stage	What CBP or the agency sees	How a wrong code shows up	Evidence that helps
ISF (ocean only)	6-digit HTSUS, origin, parties	Six digits that later disagree with the 7501	One product master feeding both filings
Entry and release	HTS number, PGA flags, targeting results	Missing or unneeded PGA data; holds	Product facts that match the chapter you chose
Entry summary review	10-digit line, value, Chapter 99 lines	Rate or additional duty that does not fit the description	Specification sheets, materials breakdown, photos
CF-28 / CF-29	Specialist’s questions or proposed change	Rate advance across many entries	Written GRI analysis, legal notes, CBP rulings
Liquidation and protest	Final duty bill	Bills, interest, a larger bond requirement	The same file, still complete years later

Two patterns cause most of the pain. The first is a code chosen once for a product family and copied to every new SKU, so a single wrong decision repeats across hundreds of entries and one CF-29 rate advance covers all of them. The second is a code that was right when chosen but sits under a Chapter 99 action added later, so the general rate is fine and the additional duty is missing. Both are classification problems, and both are cheaper to fix before the goods ship than after a specialist finds them.

TariffWolf is not a customs broker and has no part in clearing the shipment. Its work is the step before: it classifies the products your broker will declare to the 6-digit HS level and keeps the GRI reasoning, legal notes and CBP rulings for each. The broker adds the last four digits, and the answer to a CF-28 already exists when the request arrives.

A checklist before the next shipment sails

Confirm the importer number, the bond and its amount, and the broker’s power of attorney are in place.
Check that each SKU on the invoice has a 10-digit HTSUS number with a written reason, and that the ISF uses the same first six digits.
Look up the Chapter 99 lines that apply to each code and origin on the expected entry date.
Identify which SKUs need partner agency data, and have it ready before the entry is filed.
Put the invoice description, materials and function for each SKU where the person answering a CF-28 can find them.
Diary the entry date, the PSC cut-off, the scheduled liquidation date and the 180-day protest deadline.

Frequently asked questions

How long does US customs clearance take?

Release can be ready when the cargo arrives if the entry was filed in advance and nothing triggers an exam or agency hold. An exam or a partner agency review adds days that depend on the port and the agency. The financial side takes much longer: entries are liquidated 314 days after entry by default, and the protest window runs 180 days after that.

What is the difference between CBP Form 3461 and Form 7501?

Form 3461 is the entry, the request to release the goods, filed within 15 calendar days of arrival. Form 7501 is the entry summary, which declares classification, value and origin and pays estimated duty, within 10 working days after the time of entry. They can be filed together.

What is liquidation in customs?

Liquidation is CBP’s final computation of duties and fees on an entry. If CBP does not act within one year of entry and has not extended or suspended liquidation, the entry is deemed liquidated as declared under 19 USC 1504. After liquidation, the usual route to change it is a protest, filed within 180 days.

Who handles customs clearance for my shipment?

Usually a licensed customs broker files the entry and entry summary for the importer of record, though importers can file their own. Whoever files, the importer of record stays legally responsible for the classification, value and origin declared.

Can I correct an HTS code after my goods are released?

Yes, before liquidation, with a post-summary correction filed within 300 days of entry and at least 15 days before the scheduled liquidation date. After liquidation, the route is a protest within 180 days. If the error may involve a violation, talk to a licensed customs broker or trade attorney about a prior disclosure before you file anything.

Clearance rewards the importer who finished the classification work before the vessel sailed. The release stage needs a bond and a filing; the 314 days after that need a code you can explain on paper. If the reasoning for your main SKUs lives only in a broker’s memory, that is the gap to close first.

TariffWolf’s bulk classification service classifies a catalog and returns the 6-digit HS code for each product with the GRIs, legal notes and CBP rulings behind it, with an exportable audit trail per SKU. Your broker chooses the last four digits and files the entry; you keep the evidence for each code ready for a CF-28.

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