Importers of HS 5503.20 (of polyesters) from Korea, South actually paid 10.18% on the taxed portion of the value in 2026-06 — 10.18% across everything shipped, taxed or not. Measured from official duty receipts, not the rulebook: the statutory MFN base rate on this code is 4.3%. Over the window the rate on the taxed portion moved 4.3% → 10.18%, with the largest single step -4.4pp in 2026-03. Measured from official US duty receipts · as-of 2026-06 · confidence: measured, not modelled. The HTS base rate is 4.3% — importers actually paid 10.18%, so the trade-war overlay added 5.9 pts, measured at the border (not a summed rulebook estimate). Reproduce exactly: tariff_story(hs: "5503.20", origin: "Korea, South") · see it at trimtabist.com/tariffs
HS 5503.20. The schedule base rate is 4.3%; importers from South Korea actually paid 10.18% on the dutiable value in 2026-06 — the trade-war overlay added 5.9 points, measured at the border. Measured, not modelled.
Over the window the collected rate moved 4.3% (2023-07) → 10.18% (2026-06), largest single step -4.4pp in 2026-03.
Korea, South's lower duty (10.18% vs 39.3%) lets it price up to 26.4% above China at the factory and still match on duty-inclusive customs cost. But on the LATEST measured prices, Korea, South actually lands cheaper — $1.29/kg vs $3.4/kg (duty in, freight out).
All goods from South Korea · the whole tariff ledger · reproduce: tariff_story(hs: "5503.20", origin: "South Korea") via /connect. Not customs or legal advice.