How to read a 10-digit HTS code

Last updated: 2026-06-02

Every product imported into the US is classified under a 10-digit HTS code (Harmonized Tariff Schedule). Picking the right one is the single most consequential step in importing — the wrong code can mean paying 0% when you owe 25%, or vice versa.

Anatomy of a code

Take 8513.10.20.00 (a portable flashlight):

• 85 — the chapter (electrical machinery & equipment). 99 chapters cover all goods.
• 8513 — the heading (portable electric lamps with their own power source). The first 4 digits.
• 8513.10 — the subheading (lamps). The first 6 digits are the international HS code, shared by all WCO countries.
• 8513.10.20 — the US tariff line (digits 7–8) that sets the duty rate.
• 8513.10.20.00 — the statistical suffix (digits 9–10), used for trade data.

The first six digits are international; the last four are US-specific. That’s why an “HS code” from a supplier abroad gets you to the heading, but you still need the full 10-digit HTS code to determine the US duty.

Why the exact line matters

Duty rates — and Section 301 coverage — attach at the heading/subheading level. Two products that look similar can sit under different lines with very different rates. When in doubt, classification is the importer’s responsibility, and you can request a binding ruling from CBP.

Find yours

Search by keyword or digits in the HTS code lookup, or browse the HS code directory by chapter. Once you have the code, the tariff calculator shows the full stacked duty for your origin — see tariff stacking explained for why that total is usually higher than the base rate.

Informational only — not customs advice. Classification and valuation decisions are the importer’s responsibility under 19 USC §1484. For binding rulings, file CBP Form 19; for declarations, consult a licensed customs broker.