HTS Codes Explained
What a Harmonized Tariff Schedule code is, how it determines your duty rate, and where to look one up.
The Harmonized Tariff Schedule (HTS) is the classification system US Customs and Border Protection uses to identify traded products and determine the duty rate that applies to them. It's a US-specific 10-digit extension of the 6-digit international Harmonized System (HS) maintained by the World Customs Organization, which most countries use as the basis for their own tariff schedules.
Why classification matters so much
Your HTS code isn't just a label — it's the single factor that determines your base duty rate and whether Section 301, Section 232, or other additional tariffs apply at all. Two products that look identical to a non-specialist can carry very different classifications, and therefore very different total landed costs, based on details like material composition, function, or level of assembly. Misclassification, even unintentional, can result in back duties, penalties, and delayed shipments if caught in a CBP audit.
How the code is structured
A full 10-digit HTS code breaks down roughly as: the first 6 digits are the internationally standardized HS code (shared across countries), the next 2 digits are a US-specific subheading, and the final 2 digits are a statistical suffix used for trade data reporting. The first 6 digits tell you the general product category; the full 10 digits are what determines your actual duty treatment.
Where to look one up
- USITC Harmonized Tariff Schedule search — the official, authoritative source for current HTS codes and their associated duty rates, maintained by the US International Trade Commission.
- CBP CROSS (Customs Rulings Online Search System) — a searchable database of past CBP classification rulings, useful for finding precedent on how similar products have been classified.
- A licensed customs broker — for anything beyond a straightforward, well-precedented product, a broker's classification judgment is worth far more than a keyword search, particularly for products that could plausibly fall under more than one heading.
Getting certainty on an ambiguous product
If your product's classification isn't obvious, or the duty difference between plausible classifications is significant, you can request a binding ruling directly from CBP. A binding ruling is a formal determination that CBP is contractually obligated to honor on future entries of that same product, removing the classification risk entirely. It takes time to obtain, but for a product you'll be importing repeatedly, it's often worth the wait.
Chinese suppliers sometimes provide an HTS code on commercial invoices, but that code reflects their own understanding, not a US customs determination, and the responsibility for correct classification rests with the importer of record — you. Verify independently, especially on higher-value or higher-tariff-exposure products.