What an HTS code is
An HTS code is the 10-digit number that classifies a product imported into the United States. It comes from the Harmonized Tariff Schedule of the United States, which the US International Trade Commission (USITC) publishes. US Customs and Border Protection (CBP) uses the schedule to set the duty on each import.
The first six digits are the Harmonized System code. The World Customs Organization maintains that code and updates it every five years, and trade.gov notes that the six digits are the same in every country that uses it. The United States adds four digits, so the full 10-digit code is a US code.
How the 10 digits break down
Take a hex head cap screw of steel, 10 mm across. In the 2026 schedule it sits on line 7318.15.80.66:
| Digits | Level | Text in the schedule |
|---|---|---|
| 73 | Chapter | Articles of iron or steel |
| 7318 | Heading | Screws, bolts, nuts, coach screws, screw hooks, rivets, cotters, cotter pins, washers and similar articles, of iron or steel |
| 7318.15 | Subheading, the same in every HS country | Other screws and bolts, whether or not with their nuts or washers |
| 7318.15.80 | US rate line | Having shanks or threads with a diameter of 6 mm or more: 8.5% general duty |
| 7318.15.80.66 | Statistical suffix | Cap screws, under hexagonal heads |
The duty rate sits on the eight-digit line. The 10-digit lines under it carry no rate of their own, and they split the eight-digit line for trade statistics. Two products can share a rate and still need different codes.
How to find your HTS code
- Describe the product: what it is, what it is made of, what it does and how it is used. A part number or a brand name means nothing to the schedule.
- Find the heading. Under the General Rules of Interpretation printed at the front of the schedule, the terms of the headings and the section and chapter notes decide first.
- When two headings fit, the more specific description wins. When that does not settle it, the material or component that gives the goods their essential character decides.
- Go down the indented lines under the heading to the 10-digit line that fits.
- Search the CBP rulings database for products like yours, to see how CBP has read the same lines.
- When the answer is still unclear, ask CBP for a binding ruling before you import.
The lookup above runs the first four steps for you and links each code to its rulings search.
What the duty columns mean
- General: the normal rate, which applies to most countries.
- Special: lower or zero rates under trade agreements and preference programs. The letters in brackets name the programs, and General Note 3 of the schedule lists them.
- Column 2: higher rates for the few countries without normal trade relations, which General Note 3 also names.
The rate you pay also depends on the country of origin, the customs value and any additional duty. The landed cost calculator adds the duty, freight and brokerage to the price of each item.
Additional duties in Chapter 99
Chapter 99 of the schedule holds temporary changes to the duty, including additional duties on goods from some countries. Some lines carry a footnote that points there. For example, "See 9903.90.08." points to a Chapter 99 line for certain articles that are the product of Russia.
Other additional duties apply by country of origin across many lines, with no footnote on each one. Check Chapter 99 for the country you buy from before you work out the duty.
Who is responsible for the code
Under 19 U.S.C. 1484, the importer of record files the classification and the rate of duty, using reasonable care. CBP makes the final determination of the rate, not the importer. A licensed customs broker can classify goods for you, and a binding ruling settles a doubtful case before the goods arrive.
How this lookup works
Claude, an AI model made by Anthropic, reads your description against all 1,228 four-digit headings and picks up to five. It then reads every line under those headings and picks up to three codes, with the fact that decides between them.
Every code is checked against the 2026 HTS Revision 21 from the USITC, and a code that is not in the schedule is dropped. The descriptions, units, duty rates and footnotes on screen come from that data, not from the AI. Your description goes to Anthropic's API to get the answer, and ThriveAI stores none of it.