Every product imported into the United States gets a 10-digit number. That number decides how much duty you pay. Get it wrong and you overpay on every shipment, or underpay and invite penalties from Customs.

What Is an HTS Code?

HTS stands for Harmonized Tariff Schedule. The HTS code (formally the HTSUS number) is the classification assigned to a product when it enters the United States. U.S. Customs and Border Protection uses it to determine the duty rate, and your customs broker files it on every entry.

Think of it as a Dewey Decimal System for everything that crosses the border. There are over 35,000 possible codes, organized into 99 chapters covering every imaginable good, from live animals to semiconductors.

What the 10 Digits Mean

The first 6 digits are the international Harmonized System, used by more than 200 countries. The U.S. adds 4 more digits for finer distinctions.

The deeper you go, the more specific the product, and the more the duty rate can vary between neighboring codes.

Who Assigns HTS Codes?

Legally, the importer of record is responsible for the classification. In practice, the code usually comes from the supplier, the freight forwarder, or the broker, often set when the product first launched and never revisited. That is where the trouble starts: products change, materials change, and tariff rulings evolve, but the code on file stays frozen.

Why HTS Codes Matter

Two reasons, both expensive. First, the duty rate. The difference between two plausible codes can be 5 percentage points or more. On $500,000 of annual imports, a 5-point overpayment costs $25,000 every year. Second, compliance. If CBP finds you underpaid because of a wrong code, you owe back duties plus interest and possible penalties.

HTS vs. HS vs. Schedule B

These get confused constantly. The HS (Harmonized System) is the international 6-digit base. The HTSUS is the full 10-digit U.S. version used for imports. Schedule B is the separate 10-digit system used for U.S. exports. Same product, different direction, different code system.

Where to Look Up HTS Codes

The official source is the U.S. International Trade Commission's tariff search. CBP's CROSS database holds binding rulings that show how Customs classified specific products, which is often more useful than the schedule alone because it shows real decisions on real goods.

Common Mistakes

The most common errors: using the supplier's code without verifying it, classifying by what the product looks like instead of what it is made of and how it functions, ignoring Chapter 99 additional duties that stack on top of the base rate, and never re-checking codes after product or tariff changes.