Importers of HS 9404.21 (of cellular rubber or plastics, whether or not covered) from Vietnam actually paid 13% on the taxed portion of the value in 2026-06 — 12.99% across everything shipped, taxed or not. Measured from official duty receipts, not the rulebook: the statutory MFN base rate on this code is 3%. Over the window the rate on the taxed portion moved 3% → 13%, with the largest single step +10.2pp in 2025-09. Measured from official US duty receipts · as-of 2026-06 · confidence: measured, not modelled. The HTS base rate is 3% — importers actually paid 13%, so the trade-war overlay added 10 pts, measured at the border (not a summed rulebook estimate). Reproduce exactly: tariff_story(hs: "9404.21", origin: "Vietnam") · see it at trimtabist.com/tariffs
HS 9404.21. The schedule base rate is 3%; importers from Vietnam actually paid 13% on the dutiable value in 2026-06 — the trade-war overlay added 10 points, measured at the border. Measured, not modelled.
Over the window the collected rate moved 3% (2023-07) → 13% (2026-06), largest single step +10.2pp in 2025-09.
China's lower duty (3.23% vs 12.99%) lets it price up to 9.5% above Vietnam at the factory and still match on duty-inclusive customs cost. But on the LATEST measured prices, China actually lands cheaper — $2.32/kg vs $5.88/kg (duty in, freight out).
All goods from Vietnam · the whole tariff ledger · 4 CBP rulings cite this code · reproduce: tariff_story(hs: "9404.21", origin: "Vietnam") via /connect. Not customs or legal advice.