Transshipment risk for a Vietnam supply chain is the risk that goods you’re sourcing were actually made (or substantially made) in a third country, usually China, then routed through Vietnam and relabeled “Made in Vietnam” to avoid that other country’s tariffs. As of 2026, U.S. Customs and Border Protection has significantly escalated enforcement against this practice, with confirmed factory raids and a steep 40% penalty tariff (HTS 9903.02.01) applying to goods found to be transshipped, on top of any standard duties owed.
If you’re sourcing from Vietnam and haven’t specifically checked your supplier’s origin documentation, this is worth doing before your next shipment, not after a customs hold. Here’s what the rule actually is, how it’s enforced, and how to check your own exposure.
What “substantial transformation” actually means
Vietnam gets origin credit for a product only if it underwent real, substantial transformation there, the product emerges with a new name, character, or use compared to its inputs, not just a final assembly or relabeling step. U.S. Customs applies this test by examining the bill of materials, what manufacturing processes were actually performed in Vietnam, and where the major input components originated.
A factory that imports finished or near-finished Chinese components and performs only light assembly, packaging, or relabeling in Vietnam does not confer Vietnamese origin, regardless of what paperwork says. This is the core distinction CBP investigators are trained to look for, and it’s exactly what a proper third-party factory audit is designed to surface before you’re the one holding the paperwork at customs.
Where the current tariff numbers stand (as of September 2026)
Genuinely Vietnamese-origin goods currently face a baseline tariff of 12.5% under a Section 301 forced-labor tariff, on top of standard HTS duties, pushing effective rates to roughly 12.5–27.5% for most finished goods, higher for some categories like apparel and for goods also subject to Section 232 metals tariffs (50% on steel/aluminum articles, 25% on derivative products). This 12.5% rate replaced the earlier 10% Section 122 baseline, which expired at its statutory 150-day limit on July 24, 2026, a reminder that this number has moved before and is worth re-checking close to any shipment date rather than assumed fixed.
Goods identified as transshipped, genuinely made elsewhere, routed through Vietnam to disguise origin, face a separate 40% penalty tariff, with no mitigation or exclusion process currently available. This is a categorically different, much more severe outcome than the standard duty rate, and it applies regardless of whether the importer knew the true origin or not.
Red flags that a supplier may not be a genuine Vietnam manufacturer
- Unusually fast lead times inconsistent with the claimed production process (a sign that “manufacturing” may be minimal assembly of imported components).
- Reluctance or inability to quickly produce a bill of materials showing where major inputs come from.
- A factory that seems disproportionately small or new relative to the order volumes it’s quoting, a sign it may be a trading company or shell operation rather than an actual manufacturer.
- Pricing that undercuts other verified Vietnam factories by a wide margin for the same product category, which can indicate the “manufacturer” isn’t absorbing real production costs at all.
- No verifiable factory audit (SMETA, BSCI, WRAP) or resistance to a buyer-commissioned one.
How to check your own exposure
- Request the bill of materials for your specific product, including country of origin for major components, not just the finished good’s claimed origin.
- Ask what manufacturing processes are performed on-site in Vietnam versus imported pre-made, and how that maps to the “substantial transformation” standard for your specific HTS classification.
- Verify the factory independently, a physical visit, a third-party audit, or at minimum a documented virtual walkthrough, rather than relying solely on the factory’s or agent’s claims. Our factory tours and on-the-ground verification service exists specifically for this step.
- Check the factory’s real production capacity against your order volume; a mismatch is one of the clearest transshipment signals.
- Consult a customs broker or trade compliance specialist for a formal origin determination on borderline cases, particularly for higher-value or higher-volume shipments where a 40% penalty would be financially significant.
For more on how the broader tariff landscape got here, see our breakdown of what’s actually changed in Vietnam vs. China sourcing in 2026.
Frequently asked questions
Does the importer or the factory bear the penalty if goods are found to be transshipped?
The importer of record is generally the party CBP holds responsible for the duties owed on entry, which is why origin verification before shipment, not after a customs hold, is the buyer’s responsibility to manage, regardless of what the factory or agent represented.
Is a “Made in Vietnam” label or certificate of origin sufficient proof?
No. A certificate of origin is a starting document, not proof against a substantial-transformation investigation, CBP can and does look past paperwork to the actual manufacturing process when transshipment is suspected.
Does this only apply to goods originally from China?
China is the most common origin flagged in current enforcement given the scale of manufacturing relocation, but the substantial-transformation standard and transshipment penalty apply regardless of which third country the goods actually originated from.
How often is this actually enforced, or is it mostly theoretical risk?
Enforcement escalated materially through 2026, including confirmed CBP actions at China-linked factories operating in Vietnam. This has moved from a theoretical compliance risk to an active enforcement priority, treating it as low-probability is no longer a safe assumption.
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