LandedPulseWhat is a Section 301 tariff?
Section 301 of the US Trade Act of 1974 lets the United States impose additional duties in response to trade practices it has found unfair. The resulting surcharges apply on top of the normal column 1 rate, commonly at 25% ad valorem, and are assessed at entry alongside the base duty.
The practical consequence for an importer is that the published base rate for a heading understates the charge. A product with a 2.6% base rate sourced from a covered origin can clear at 27.6% once the surcharge applies, and the difference lands on a margin that was quoted months earlier.
Coverage is defined by lists of tariff subheadings, and those lists are amended. A heading can enter or leave the scope without the base rate in the schedule changing at all, which is why monitoring the surcharge programme is a separate problem from reading the tariff schedule.
Section 232 works differently — it is a national-security instrument applied to categories such as steel, aluminium, copper, vehicles and wood products — but has the same effect on a landed cost calculation: an additional charge that a base rate lookup does not reveal.
For US routes these duties are calculated from the official HTSUS Chapter 99 and shown line by line with their 9903 heading. Where a duty depends on something the query does not state — a product exclusion granted by the USTR, the end use of the goods, or an origin claim under USMCA — the report names that condition instead of assuming it either way.
Last reviewed . General guidance on import duty mechanics, not customs or tax advice for a specific shipment.