Trade Policy, Tariffs, Customs and Forced-Labour Rules

A tariff is a tax on imports paid by the importer of record when goods enter the US, not by the exporting country — and between 2018 and 2026 it became the most volatile cost in American supply chains. The legal authority matters as much as the rate, because each authority can be imposed, stacked, excluded, struck down or refunded differently. The sequence: Section 301 tariffs on China (Lists 1–4A, Jul 2018–Sep 2019, 7.5–25%, raised on strategic goods by the 2024 four-year review); Section 232 "national security" tariffs on steel (25%) and aluminium (10%) from 23 Mar 2018, both raised to 50% from 4 Jun 2025 and extended in 2025–26 to autos, copper, trucks, timber and furniture, advanced chips and patented pharmaceuticals; IEEPA tariffs from Feb 2025 ("fentanyl" duties on Canada, Mexico and China; "reciprocal" duties on almost every country from 5 Apr 2025), which the Supreme Court held unlawful on 20 Feb 2026 (Learning Resources v. Trump, 6–3); a 10% Section 122 surcharge from 24 Feb to 24 Jul 2026 (a 15% increase was announced but never proclaimed); and from 24 Jul 2026 a new Section 301 action on 60 economies framed around forced-labour enforcement, at 10% or 12.5%, excluding goods already under Section 232 (USTR notice of action 23 Jul 2026; country tiers in the Federal Register annex). Around the tariffs sit the rest of customs: classification in the Harmonized Tariff Schedule (HTSUS), valuation, country of origin, the end of the $800 de minimis exemption (for China and Hong Kong 2 May 2025; suspended for all countries 29 Aug 2025 and kept after the ruling), antidumping and countervailing duties, the Uyghur Forced Labor Prevention Act (rebuttable presumption from 21 Jun 2022; Entity List expanded to 187 entities on 3 Aug 2026, plus three more on 29 Oct 2026), USMCA origin rules (the US declined to confirm the agreement's 16-year extension at the 1 Jul 2026 joint review, triggering annual reviews), refunds of IEEPA duties (CBP's CAPE portal from 20 Apr 2026), and Europe's carbon border tax. This section explains how a tariff is set and paid, the 2018–26 sequence authority by authority, refunds, de minimis, forced-labour rules, origin and AD/CVD, the EU, and the customs broker's role. A worked example compares duty mitigation by first sale, drawback and a foreign-trade zone; a checklist covers compliance. Rule 10 of this knowledge base applies: every rate below is given with its authority and date in force, and announced rates are not treated as rates in force. Nothing here is legal or customs advice.