Verified against HTSUS Rev. 14 · updated monthly · changelog
If you import power adapters, Vietnam origin cuts the effective duty on HTS 8504.40.85 from 37.5% to 12.5% — a 25-point swing, because Vietnam avoids the 25% List 3 Section 301 that applies to Chinese-origin goods. Current Vietnam tariffs on a switching adapter are a 0% base rate plus the 12.5% Section 301 forced-labor duty; China pays those same layers plus the 25% List 3 Section 301. That is the headline — but the rate only holds if the origin does, and duty is not the only line that moves when you switch countries.
Vietnam tariffs vs China tariffs on power adapters
| Layer, HTS 8504.40.85 | China | Vietnam |
|---|---|---|
| MFN base rate | 0% | 0% |
| Section 301 (List 3) | 25% | — |
| Section 301 forced-labor | 12.5% | 12.5% |
| Effective rate | 37.5% | 12.5% |
On a $100,000 entry, that is $37,500 in duty from China versus $12,500 from Vietnam — a $25,000 difference, roughly the gross margin on the goods. For every layer and its authority, and the adjacent HTS codes, see the duty stack for power products.
What Vietnam origin actually requires
The 12.5% rate is not a shipping address — it is a country-of-origin determination. For a switching power supply, CBP looks at where transformer winding, PCB assembly, programming, and test occur. Do that work in Vietnam and the adapter is Vietnamese, even with some Chinese components inside. Do only final assembly of finished Chinese subassemblies and it stays Chinese — declaring otherwise is transshipment, assessed the full Chinese-origin rate with every duty layer reinstated, plus penalties.
Before you re-source, get the four documents and, for a high-volume SKU, a binding ruling — the full checklist is in how to verify a Vietnam country of origin.
China vs Vietnam, beyond the tariff line
Tariff is the biggest number, but not the only one. The honest comparison for a power-adapter buyer:
| Factor | China | Vietnam |
|---|---|---|
| Section 301 exposure | 25% (List 3) | None, if substantially transformed |
| Effective duty, 8504.40.85 | 37.5% | 12.5% |
| Component ecosystem | Deepest; most sub-tiers domestic | Maturing; some inputs still cross the border |
| Origin scrutiny at CBP | Established, lower-risk paperwork | Higher — entries sampled for transshipment |
| Best fit | Lowest unit cost, existing tooling | Tariff-driven origin; China-plus-one |
The pattern most buyers land on is China-plus-one: keep the Chinese capability, add Vietnam as a second origin on the same drawing set, and elect the origin that fits each order’s tariff math. It is an origin strategy, not a factory move — and it only works when both origins run one engineering and test system. That is how Kestner’s core power lines are built; the Sourcing page covers how we vet and document each origin.
How to run the numbers
Duty is one input to landed cost. To compare two origins honestly, add duty to unit price, freight, and the carrying cost of longer or shorter lead times — then decide. A quote that beats the Vietnam column by relabeling is not a lower landed cost; it is a deferred full-rate penalty. We price in USD with the tariff and landed-cost math shown, and reprice your quote the week any duty layer changes.
Sources
- Section 301, List 3 — 25% on Chinese origin84 FR 20459
- Section 301 forced-labor duty (both origins) — 12.5%, eff. 2026-07-24USTR Section 301 (forced-labor action)
- MFN base rate, 8504.40.85HTSUS Rev. 14 (2026)
Frequently asked
What are the current Vietnam tariffs on power adapters?
As of July 24, 2026, a switching power adapter of Vietnamese origin under HTS 8504.40.85 pays an effective 12.5% — a 0% MFN base rate plus the 12.5% Section 301 forced-labor duty. It avoids the 25% List 3 Section 301 that applies to Chinese-origin adapters, so the same adapter from China pays 37.5%.
Is it cheaper to import power adapters from Vietnam or China?
On duty, Vietnam is 25 points cheaper: 12.5% vs 37.5% effective on HTS 8504.40.85, because Vietnam origin drops the 25% List 3 Section 301 layer. Whether that makes total landed cost lower depends on unit price, MOQ, and lead time — but on a $100,000 entry the duty difference alone is $25,000.
Does moving production to Vietnam automatically lower my tariff?
No. The lower rate applies only if the adapter is substantially transformed in Vietnam — transformer winding, PCB assembly, programming, and test done there. Final assembly of Chinese subassemblies remains Chinese origin, and declaring it Vietnamese is transshipment, assessed the full Chinese-origin rate.
What is China-plus-one for power products?
China-plus-one means keeping Chinese capability while adding a second-country origin — for power products, typically Vietnam — so you can elect the origin that controls your tariff exposure on a given order. It is an origin strategy, not a factory move, and it works only when both origins run the same engineering and test.
Changelog
We verify monthly whether or not anything changed, and say so. Corrections: write to us — fixes are published here with the date.
The tariff answer is only half of it.
Vietnam’s 25-point advantage only survives if the origin is real. Our core power lines build in both Vietnam and China on one drawing set — so you can elect the origin and get it documented per unit, instead of relabeling your way into a full-rate penalty.
Request a quote