Identify the 10-digit HTS code for the commodity (see HS classification route); navigate to the USITC HTS Online portal or query a tariff API that exposes the current HTS schedule.
Look up the HTS code in the schedule and read the General (MFN/Column 1) duty rate, the Special (GSP/FTA) rates for applicable countries, and the Column 2 rate for non-MFN countries.
Check the USTR Section 301 list for the specific HTS code if the goods originate from China; Section 301 tariffs add 7.5%, 25%, or other percentage duties on top of the MFN rate and must be declared on the entry.
Search CBP's ADD/CVD case reference for the HTS code and country of origin to identify any antidumping or countervailing duty (AD/CVD) orders; AD/CVD rates can far exceed MFN rates and are enforced via cash deposit at entry.
Sum all applicable duties (MFN + Section 301 + AD/CVD) to produce a total duty rate for landed cost calculation; note that AD/CVD rates are subject to annual administrative review and may be retroactively adjusted.
Known gotchas
Tariff schedules are updated frequently — at minimum annually for HTS schedule revisions and on an ad-hoc basis for Section 301 exclusions and reinstatements; do not cache tariff lookups for more than a few days without a mechanism to detect updates.
The country of origin for duty purposes is not always the country of shipment; substantial transformation rules apply, and goods assembled in a third country from Chinese components may still be subject to Section 301 depending on origin determination.
AD/CVD cash deposit rates at entry are preliminary; final assessed rates are set after administrative review and can result in a bill for additional duties years after import — importers must plan for this contingency when costing imported goods.
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp