Importers of HS 8544.30 (ignition wiring sets and other wiring sets of a kind used in) from Vietnam actually paid 13.58% on the taxed portion of the value in 2026-06 — 13.46% across everything shipped, taxed or not. Measured from official duty receipts, not the rulebook: the statutory MFN base rate on this code is 5%. Over the window the rate on the taxed portion moved 5% → 13.58%, with the largest single step +16.9pp in 2025-05. Measured from official US duty receipts · as-of 2026-06 · confidence: measured, not modelled. The HTS base rate is 5% — importers actually paid 13.58%, so the trade-war overlay added 8.6 pts, measured at the border (not a summed rulebook estimate). Reproduce exactly: tariff_story(hs: "8544.30", origin: "Vietnam") · see it at trimtabist.com/tariffs
HS 8544.30. The schedule base rate is 5%; importers from Vietnam actually paid 13.58% on the dutiable value in 2026-06 — the trade-war overlay added 8.6 points, measured at the border. Measured, not modelled.
Over the window the collected rate moved 5% (2023-07) → 13.58% (2026-06), largest single step +16.9pp in 2025-05.
Vietnam's lower duty (13.46% vs 34.98%) lets it price up to 19% above China at the factory and still match on duty-inclusive customs cost. But on the LATEST measured prices, Vietnam actually lands cheaper — $21.21/kg vs $29.86/kg (duty in, freight out).
2 Chapter-99 measures name Vietnam; scope mapping is partial (several annexes are PDFs) — absence never means exemption. They do not sum, and some are product-specific — the collected rate above is the composed truth.
All goods from Vietnam · the whole tariff ledger · 3 CBP rulings cite this code · reproduce: tariff_story(hs: "8544.30", origin: "Vietnam") via /connect. Not customs or legal advice.