In the last issue we drew the line the 2025 framework put through every US import from Vietnam: 20% for goods with genuine Vietnamese origin, 40% for goods judged to be transshipped. We called the gap between them a tax on paperwork. This issue is the paperwork — what origin actually is in law, how a factory earns it, and what a file has to contain to survive the question when it comes.

There is no shortcut, because there is no treaty

Start with what the US and Vietnam do not have: a free-trade agreement. The preferential certificates that matter elsewhere — Form EAV into Europe under the EVFTA, Form D across ASEAN — buy you nothing at a US port, because there is no preferential rate to claim. What governs a US entry is non-preferential rules of origin: the plain question of which country a good is from, for the purpose of marking, trade remedies and now the framework's reciprocal rate.

That matters because it removes the comforting idea that a certificate is a formality. There is no treaty doing the work for you. The origin has to be real on its own terms, and the framework's 40% transshipment rate is the price of failing to show it.

The two ways a good becomes Vietnamese

Origin is earned one of two ways, and every honest file rests on one of them.

Wholly obtained. The good is entirely of Vietnam — minerals mined there, plants grown there, or products made only from those things. Simple to prove, and rare in building materials, which almost always start from imported inputs.

Substantially transformed. The realistic case. A good made partly from foreign inputs takes on Vietnamese origin when it is substantially transformed in Vietnam — turned into something with a new name, character and use. In practice that test is applied through one of two lenses:

  • a change in tariff classification — the imported inputs sit under different HS codes than the finished good that leaves the factory; or
  • a regional value content threshold — a minimum share of the finished good's value is added in Vietnam.

The distinction sounds technical. It is the whole game. Grinding, polishing, repacking or bolting on a handle is not substantial transformation. Pressing and firing raw bodies into finished porcelain is. The framework's penalty exists precisely to catch goods that cleared the first bar while pretending to have cleared the second.

The certificate is the claim; the file is the proof

A Vietnamese certificate of origin — issued by an authorised body such as the Ministry of Industry and Trade or the Chamber of Commerce (VCCI) — is the document that travels with the shipment. Buyers treat it as the finish line. It is the starting line.

A certificate asserts origin. What substantiates it is the file behind it, and that file is what a US Customs officer, or your own auditor, actually tests:

  • A bill of materials that reconciles — the inputs, their HS codes and their countries, tied to the finished good's classification so the change in tariff heading is visible, not asserted.
  • Production records — work orders, batch and kiln logs, output tallies that match the quantity on the invoice. A factory that made the goods can show it made the goods.
  • Mill and supplier certificates for the inputs, so the chain doesn't go dark one tier up.
  • A factory that survives a site visit — real lines, real capacity, matching the volumes on the paper.

When those reconcile, the certificate means what it says. When they don't — when the "factory" is a warehouse and the production record is thinner than the invoice — the certificate is the most dangerous document in the file, because it puts a false claim in writing.

The tear everyone should watch for

There is one failure mode behind most transshipment cases, and it is worth naming plainly. A near-finished Chinese good is brought into Vietnam, given a token final step — a repack, a light assembly, a relabel — and presented as Vietnamese-made. It clears no real transformation test. It is exactly the case the 40% rate was written for, and exactly the case a buyer inherits if they took the factory's word instead of verifying it.

This is why origin cannot be outsourced to a supplier's assurance. The buyer carries the landed-cost risk, so the buyer — or a desk acting for them — verifies origin before booking: the transformation, the file, the factory. It is unglamorous work, and under this framework it is the work that decides whether your container clears at 20% or 40%.

That verification is the quiet product underneath every proposal we send. It is also what makes the next issue possible: in "$17 Billion of Wood" we take Vietnam's record timber year — and the live US trade-remedy scrutiny over it — and show why, at that scale, the file has to be flawless.

Sources & data notes

This brief describes non-preferential rules of origin and origin-documentation practice in general terms — wholly-obtained and substantial-transformation tests, change-in-tariff-classification and regional-value-content methods, and Vietnamese certificate-of-origin issuance — alongside the transshipment provisions of the October 2025 US–Vietnam framework discussed in The 20% Line. Specific origin criteria, thresholds and required documents vary by product, HS code and the current rules in force. This is orientation, not legal or customs advice — confirm the applicable rule and evidence for your goods with a qualified customs broker or counsel before you rely on it.

Want origin verified before you commit, not discovered at the port? Send us one BOM and each line comes back with its origin position accounted for — transformation, file and factory — inside 48 hours. Our own fiber-cement line, DURAGREEN®, ships under the same discipline we apply to everything we source.