Three inputs behind the number
The base rate comes from the Harmonized Tariff Schedule of the United States, so the first question is how the product is classified, which turns on what it is and how the tariff headings and notes describe it. The second is country of origin, which decides whether a special rate under a trade agreement or preference program applies and whether extra tariffs aimed at particular countries reach the goods. The third is value, since most duties are calculated as a share of the transaction value declared at entry, with adjustments for items such as assists or royalties. A change in any one of these can change the amount owed. Your broker files the entry, but the importer of record remains responsible for using reasonable care.
Additional tariffs and a moving target
On top of the ordinary rate, many goods have been subject to additional tariffs imposed under trade and national security authorities, and those measures have changed often. In 2026 the Supreme Court held that tariffs imposed under the International Emergency Economic Powers Act were unlawful, and CBP set up a staged refund process whose eligibility rules should be checked, while other tariff measures remain in effect or are being contested. Because the rate that applies is generally the one in effect when goods are entered, keep entry summaries, broker statements, and commercial invoices organized by date. Before relying on a rate for pricing or contracts, confirm the current status for your specific product and origin.
Questioning a rate
If you think a rate is wrong, the route depends on timing. Before importing, you can ask CBP for a binding ruling on classification or origin, which gives you a basis for planning. After entry but before liquidation, a post-summary correction can often fix an error. After liquidation, a protest must be filed within a set period, and a denied protest can be taken to the Court of International Trade. If past entries were underpaid, a prior disclosure may reduce penalty exposure, but it should be prepared carefully. We review the product, its classification history, and the entry records to see which route fits.
