Importers of HS 8544.30 (ignition wiring sets and other wiring sets of a kind used in) from Korea, South actually paid 8.75% on the taxed portion of the value in 2026-06 — 6.5% 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% → 8.75%, with the largest single step +19.3pp 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 8.75%, so the trade-war overlay added 3.8 pts, measured at the border (not a summed rulebook estimate). Reproduce exactly: tariff_story(hs: "8544.30", origin: "Korea, South") · see it at trimtabist.com/tariffs
HS 8544.30. The schedule base rate is 5%; importers from South Korea actually paid 8.75% on the dutiable value in 2026-06 — the trade-war overlay added 3.8 points, measured at the border. Measured, not modelled.
Over the window the collected rate moved 5% (2023-07) → 8.75% (2026-06), largest single step +19.3pp in 2025-05.
Korea, South's lower duty (6.5% vs 34.98%) lets it price up to 26.7% above China at the factory and still match on duty-inclusive customs cost. But on the LATEST measured prices, Korea, South actually lands cheaper — $23.45/kg vs $29.86/kg (duty in, freight out).
2 Chapter-99 measures name Korea, South; 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 South Korea · the whole tariff ledger · 3 CBP rulings cite this code · reproduce: tariff_story(hs: "8544.30", origin: "South Korea") via /connect. Not customs or legal advice.