First sale for export lowers the price you start from. This post is about the opposite problem: items the law requires you to add back on top of that price, first sale or not, because they are part of the real cost of getting the goods produced and into your hands. Miss one and you have understated your customs value, whichever method got you to the starting number.
Under the WTO Agreement on Implementation of Article VII of the GATT 1994 (the Customs Valuation Agreement), Article 8 lists what must be added to the price actually paid or payable when it is not already in the invoice: certain commissions and brokerage, container and packing costs, assists, royalties and license fees, and any proceeds of a later resale that flow back to the seller. The United States implements this through 19 U.S.C. 1401a(b), with the operative Customs and Border Protection (CBP) regulation at 19 CFR 152.103. The two frameworks line up closely; this post uses the US statute and regulation as the worked reference, noting the WTO article alongside each addition.
The five additions, side by side
19 U.S.C. 1401a(b)(1) requires adding five things to the price actually paid or payable, to the extent each is not already included and is based on sufficient information:
| Addition | US statute | WTO Article 8 basis | Added when |
|---|---|---|---|
| Packing costs | 1401a(b)(1)(A) | Art. 8.1(a)(ii) | Incurred by the buyer |
| Selling commission | 1401a(b)(1)(B) | Art. 8.1(a)(i) | Incurred by the buyer; buying commissions are excluded |
| Assists | 1401a(b)(1)(C) | Art. 8.1(b) | Supplied free or at reduced cost by the buyer |
| Royalty or license fee | 1401a(b)(1)(D) | Art. 8.1(c) | Buyer must pay it, directly or indirectly, as a condition of the sale |
| Proceeds of subsequent resale | 1401a(b)(1)(E) | Art. 8.1(d) | Any part accrues, directly or indirectly, to the seller |
If CBP cannot get sufficient information to quantify one of these, transaction value cannot be used for that entry at all, and the importer falls back to deductive value, computed value or another method. Under-declaring is not the only risk; an addition you cannot document can knock you out of transaction value entirely.
Assists: tooling, dies, molds and design work you provide for free
An assist is something the buyer supplies to the foreign producer, free of charge or at reduced cost, for use in producing or selling the imported goods, its value not otherwise reflected in the price paid. 19 CFR 152.102 defines four categories: materials and components incorporated into the merchandise; tools, dies, molds and similar production items; merchandise consumed in production; and engineering, development, artwork, design work and plans and sketches undertaken outside the United States.
That last category catches arrangements that do not look like a physical shipment at all. If your US design team hands a factory in Vietnam a finished CAD file for a custom mold, or your engineer flies out and does development work on site, and the factory does not charge you for it, that work is an assist, even though nothing physical crossed the border with a price tag on it. The one narrow exception: engineering, development, artwork, design work and plans and sketches undertaken inside the United States are not assists.
How assist value gets apportioned across your entries
19 CFR 152.103(d) sets the valuation method by category. Materials, components and merchandise consumed in production are valued at your cost of acquisition, or your cost of production if you made them yourself. Tools, dies and molds are valued the same way, adjusted downward to reflect prior use if the tooling was not new when you supplied it, or at the cost of leasing if you leased rather than bought it.
You almost never pay tooling cost as a lump sum against one shipment, so 19 CFR 152.103(e) gives importers a choice of apportionment methods: spread the value over the first shipment, over the units actually produced up to the first shipment, or over your entire anticipated production run, using a method that is reasonable and consistent with generally accepted accounting principles. Pick one, apply it consistently, and keep the calculation on file; an assist apportioned differently entry to entry with no documented method is exactly what an audit flags.
Royalties and license fees: the condition of sale test
A royalty or license fee gets added to the customs value only when the buyer is required to pay it, directly or indirectly, as a condition of the sale of the imported merchandise for exportation to the United States. That condition-of-sale language is doing the real work: a royalty that is genuinely optional, or that has nothing to do with getting the goods sold to you in the first place, does not belong in the dutiable value even if you pay it to the same company that manufactured the goods.
CBP applies a three-question test from a 1993 General Notice on the dutiability of royalty payments, still the working framework as of September 2026:
- Was the imported merchandise manufactured under patent?
- Was the royalty involved in the production or sale of the imported merchandise?
- Could the importer buy the product without paying the fee?
Affirmative answers to the first two questions and a negative answer to the third point toward dutiable. A royalty is also more likely dutiable when the licensor and the seller are the same entity and the fee is paid straight to the seller, because that makes it harder to argue the payment is unrelated to the sale. CBP has separately confirmed that a trademark royalty is dutiable regardless of how it is calculated, against the purchase price or against net sales, once it meets the condition-of-sale test; the calculation method alone does not decide dutiability.
When a royalty is not dutiable
Two carve-outs matter in practice. The interpretive notes to WTO Article 8 and the US regulation exclude charges for the right to reproduce the imported goods in the country of importation, and CBP guidance similarly treats fees paid purely for US distribution or resale rights as non-dutiable when they are not a condition of the international sale. And in rulings where CBP has found a royalty non-dutiable, the reasoning follows the same pattern: the fee was tied to domestic production or domestic sales after importation, not to the import transaction; the importer did not have to pay it to obtain the goods; and it had no effect on the price or delivery of the imported articles.
The practical version: a royalty a US distributor pays to a brand owner for the right to resell branded goods domestically, calculated on domestic resale revenue and payable regardless of any particular shipment, is a strong candidate for non-dutiable. A fee the same distributor must pay before the factory will release the goods for export, calculated on the imported quantity, is a strong candidate for dutiable. Most real arrangements sit between those two, which is why CBP treats this as case-by-case, and why a binding ruling before you structure a licensing deal is worth the wait; our guide to customs binding rulings covers how to request one.
Proceeds of a subsequent resale that flow back to the seller
The least common of the five additions, and the easiest to overlook, is 1401a(b)(1)(E): if any part of the proceeds from a later resale, disposal or use of the imported merchandise accrues, directly or indirectly, back to the seller, that amount is added to the customs value. This shows up where the foreign seller keeps a profit-sharing stake in what happens after importation, for example a revenue-share or an earn-out tied to your downstream resale price, rather than being paid entirely through the invoice. If your supplier agreement sends any money back to the seller based on how well the goods sell once landed, check whether it needs to be added to the entries it relates to.
Packing costs
Packing costs are the most mechanical of the five: the cost of containers, coverings, and the labor or materials used to get the merchandise packed and ready for shipment to the United States, when the buyer incurs that cost and it is not already in the invoice price. Instruments of international traffic, reused shipment after shipment rather than consumed in packing one order, are excluded. If your supplier bills export packing as a separate line item, it still belongs in the dutiable value; separating it on the invoice does not remove the obligation to declare it.
Selling commissions versus buying commissions
A selling commission, defined in 19 CFR 152.102 as a commission paid to an agent who is related to, or controlled by, or works for or on behalf of, the manufacturer or seller, is added to the customs value when the buyer incurs it. A bona fide buying commission, paid to an agent who genuinely represents the buyer abroad in sourcing and purchasing the goods, is excluded and is one of the few costs in this whole framework you get to leave out. Both the WTO agreement and the US statute carve out buying commissions by name, treating them as a cost of the buyer doing its own sourcing rather than a cost of the sale.
The dividing line is not the label on the invoice. CBP looks at the substance: whose instructions the agent actually follows, whether it can bind the seller to a sale, who bears the risk if the goods do not conform, and whether the fee is contingent on the outcome of the purchase or paid regardless. An agent who takes title, sets prices, or answers to the seller functions as a selling agent no matter what the contract calls the payment, and a commission paid to that agent is dutiable. Keep the buying agency agreement and correspondence showing the agent acts for you, not the seller; that is what CBP will ask for if the exclusion is challenged.
How this differs from first sale for export
It is worth being precise about how these two topics relate, because they get confused. Our guide to first sale for export is about which transaction price you are allowed to start from in a multi-tiered supply chain: the earlier, lower manufacturer-to-middleman price instead of the higher middleman-to-importer price. This post is about what you then have to add on top of that starting price, whichever one you legitimately use. The two rules do not cancel each other out: an importer using first sale still has to add the value of any assist it supplied, any dutiable royalty, and any packing or selling commission cost it incurs, on top of the lower first sale price. Skipping the additions because you already saved money on the base price does not make them optional; it just means you understated the value by more.
For the mechanics of how the dutiable value gets built up in general, our broader guide to customs valuation covers the full hierarchy of methods. These additions are separate from origin-based and quantity-based duty regimes that sit on top of the same customs value, including anti-dumping and countervailing duties and tariff-rate quotas; getting the base value right matters for all of them, because each is typically calculated as a rate applied against that same customs value.
A worked example (illustrative numbers only)
These figures are hypothetical and for illustration only; they are not a real transaction or a benchmark for what any category of goods should cost.
| Line item | Amount | Treatment |
|---|---|---|
| Invoice price paid to the factory | $50,000 | Starting price actually paid or payable |
| Mold supplied to the factory free of charge, apportioned over this shipment | $2,000 | Add: assist, 1401a(b)(1)(C) |
| License fee paid to the brand owner as a condition of the factory releasing the goods | $1,500 | Add: royalty, 1401a(b)(1)(D) |
| Export packing, billed separately by the factory | $300 | Add: packing costs, 1401a(b)(1)(A) |
| Fee paid to a sourcing agent who represents the importer, does not take title, and is paid a flat fee regardless of outcome | $800 | Excluded: bona fide buying commission |
| Customs value | $53,800 | $50,000 + $2,000 + $1,500 + $300; the $800 buying commission is not added |
Checklist for your customs compliance file
- Records of anything supplied free or at reduced cost to a foreign producer: tooling, dies, molds, materials, or design and engineering work done outside the United States, with cost or production records to support the value.
- A documented, consistent apportionment method for any assist that benefits more than one shipment.
- Every royalty or license agreement connected to the imported goods, plus correspondence showing whether payment is genuinely a condition of the sale or tied to domestic production and resale after importation.
- A buying agency agreement, where one exists, showing the agent represents you: whose instructions it follows, that it does not take title or bind the seller, and how its fee is structured.
- Packing cost invoices, even when billed as a separate line item.
- Any supplier or distribution clause that sends money back to the seller based on your downstream resale, disposal or use of the goods, reviewed against 1401a(b)(1)(E).
Our guide to the import documentation checklist covers the broader record-keeping obligation these additions sit inside; an addition you cannot document is one CBP can challenge on audit even if you declared it correctly at the time.
What to do next
None of this is optional depending on which valuation method you use, and getting it wrong understates duty owed, which is a materially worse outcome than overpaying. If your supply chain involves free-issued tooling, a license agreement, or a sourcing agent whose role is not clearly documented, resolve it with a customs broker or trade counsel before your next entry, not after CBP asks about it.
A forwarder or customs broker who regularly handles your product category and lane will have seen how these additions get treated in practice. You can search freight forwarders and customs brokers by country and service in the CargoLinked directory, or post your shipment on the public requests board and let forwarders who cover that lane respond with quotes.
This article explains a legal framework in general terms and is not legal or customs advice. Dutiability of a royalty, license fee or commission depends on the specific facts of your transaction; confirm your own treatment with a licensed customs broker, trade counsel, or a binding ruling from CBP before relying on it.
