Customs Valuation: How the Dutiable Value Is Actually Calculated

Duty is a percentage of a number, and most importers never examine how that number is built. Customs value is not simply your invoice price. Some costs are added to it by statute, some are excluded only if you itemise them, and in the US the value is an FOB-equivalent rather than a landed cost, which surprises importers used to other jurisdictions.

General information, not legal advice, and US-specific. For a binding answer, request a valuation ruling or take licensed advice. Verified against the statute and current regulations in August 2026.

Six methods, in a fixed order

The statute sets a hierarchy. Each method is available only if the one above it cannot be determined:

1. Transaction value: the price actually paid or payable, adjusted. Used for the overwhelming majority of entries.
2. Transaction value of identical merchandise
3. Transaction value of similar merchandise
4. Deductive value: worked back from the US resale price
5. Computed value: built up from production cost plus profit and general expenses
6. The value provided for under subsection (f): a flexible application of the earlier methods

Two details worth knowing. The importer may swap the order of methods 4 and 5 on request, taking computed value before deductive. And method 6 has no statutory name: "fallback", "residual" and "derived" are all trade shorthand, not the language of the law.

What the price actually paid or payable includes

It is the total payment for the goods, whether direct or indirect, made by the buyer to or for the benefit of the seller. So a payment you make to a third party that discharges the seller's obligation is still part of the price. A price reduction agreed after importation is disregarded.

International freight and insurance are carved out of the definition itself: they are never in the value, with no conditions attached. This is why US customs value is FOB-equivalent rather than CIF.

The five additions, and no others

The statute says these five "and no others". The list is closed, so there is no sixth category CBP can invent.

Buying commissions are not dutiable. This is the most commonly misstated point in the whole area. A commission paid to your own agent, acting for you, is not on the list. Only a commission paid to an agent acting for the seller is. Royalties are similarly conditional and decided case by case. Do not treat them as dutiable as a class.

The trap in the additions

Each addition counts only if it is not already in the price and is based on sufficient information. If sufficient information is not available for any one of them, the consequence is not an estimate: transaction value cannot be determined at all, and the entry drops to method 2. Poor records on a single royalty can therefore cost you the use of the primary valuation method entirely.

Assists: the category everyone forgets

An assist is something you supply to your supplier free of charge or at reduced cost, for use in producing or selling the goods. Four categories:

1. Materials, components and parts incorporated in the goods
2. Tools, dies, moulds and similar items used in production
3. Merchandise consumed in production
4. Engineering, development, artwork, design work, plans and sketches

Category four carries a geography rule that is genuinely useful. It is an assist only if the work was undertaken outside the United States. Design and engineering performed in the US and supplied free to a foreign factory adds nothing to customs value. The identical work done abroad does.

If you send moulds, tooling or free components to your supplier, you almost certainly have assists to declare. Not doing so is a common and entirely avoidable compliance failure.

Buying from a related party

Relatedness, which includes anyone holding 5% or more of the voting stock, among seven categories, never disqualifies transaction value by itself. It survives if either:

• The circumstances of the sale show the relationship did not influence the price. The recognised routes are that the parties deal as if unrelated, that the price follows normal industry pricing practice, or that it recovers all costs plus a profit equivalent to the firm's overall profit on that class of goods.
• A test value closely approximates it: the transaction, deductive or computed value of identical or similar goods exported at about the same time.

There is no fixed percentage for "closely approximates"; CBP states it cannot apply a uniform standard. And if CBP rejects your declared value in a way that increases duty, you must be told the grounds and given 20 days to respond in writing.

First Sale: still available in 2026

In a multi-tier transaction (factory sells to a middleman, middleman sells to you) you may be able to declare the earlier, lower price. CBP reaffirmed in an October 2025 ruling that appraisement on a bona fide sale prior to the last sale for export is a legitimate basis of appraisal, and it is still actively deciding first sale cases. The most recent published ruling in this line is dated 7 August 2026. The doctrine is in current use, not merely surviving on paper.

Three conditions, from the governing case law:

1. A bona fide sale at each tier, real transfer of title and risk for real consideration. Labels in the paperwork are indicative, not decisive.
2. The goods were clearly destined for export to the United States at the time of that first sale.
3. The sale was at arm's length, free of non-market influences.

The burden is entirely yours. CBP presumes the value is the price you paid, and you must rebut that with documentary evidence. Recent rulings denying first sale claims have turned on exactly this, in one 2025 decision, supporting records were not accepted because they had not been translated into English. The doctrine is secure; individual claims fail on evidence.

Two pieces of stale guidance to ignore

• The 2008 proposal to abolish first sale was withdrawn in September 2010, not 2008. A lot of commentary gets the date wrong.
• The first-sale declaration requirement expired on 19 August 2009 and no longer exists in the regulations. CBP's own website still describes it in the present tense, so an importer researching this today can easily be misled by the agency itself.

One thing genuinely worth watching: a bill introduced in February 2026 would replace first sale with a last-sale rule. As of August 2026 it has not advanced past committee referral and is not law. A bill in committee changes nothing today.

Where value reduction actually helps

Any duty charged as a percentage of entered value shrinks proportionally when customs value falls, which is why first sale attracts attention:

• Section 301, yes. Both the long-standing China action and the broader forced-labour action effective 24 July 2026, covering 60 economies, are additional ad valorem duties on customs value.
• Section 232: yes, and the benefit grew. Until April 2026 the duty on many derivative articles attached only to the metal content, which limited what a lower article value achieved. From 6 April 2026 it applies to the full customs value regardless of metal content, so first sale now reduces the entire Section 232 base rather than a slice of it. Guidance written before that date understates this.
• Anti-dumping and countervailing duties, indirectly. Commerce sets the rate by a calculation that does not use customs value at all, so first sale cannot change it. That rate is then applied to entered value, so a lower entered value does produce a lower deposit and assessment. The exception is a per-unit rate, where entered value is irrelevant and first sale delivers nothing.
• IEEPA-based tariffs, moot. Struck down in February 2026 and being refunded.

The China myth worth retiring

You will be told first sale does not work for Chinese goods because China is a non-market economy. That is not the law. The Federal Circuit held in 2022, and reaffirmed in December 2024, that there is no basis in the statute for considering non-market-economy effects in a transaction value analysis. The "free from non-market influences" wording in the governing test is a generic arm's-length condition applied to every transaction regardless of origin.

What is true is that first sale claims on Chinese supply chains fail more often: for evidentiary reasons. Related factory and middleman structures are more common, records are more often untranslated, and profit statements more often report firm-wide rather than same-class-of-goods profit. The bar is identical; clearing it is harder.

If the amounts justify it, get certainty in advance. See how binding rulings work. Related: rules of origin, calculating import duty and duty drawback.

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