Harmonized Tariff Schedule (HTS): A Plain-English Guide

The Harmonized Tariff Schedule of the United States (HTSUS) is the official list that assigns every imported product a numeric code and the duty rate tied to it. Get the code right and your goods clear customs at the correct rate; get it wrong and you face the wrong duty, delays, or penalties. This guide explains how the schedule is built, how to read a code, and where to get certainty when classification is genuinely unclear.

Who Maintains the HTS

The HTSUS is published and maintained by the U.S. International Trade Commission (USITC). It is built on the international Harmonized System (HS) — a global product nomenclature administered by the World Customs Organization (WCO) and used by virtually every trading nation. Because the first six digits are internationally standardized, an HS code means the same thing in the U.S. as it does in the countries you buy from or sell to. U.S. Customs and Border Protection (CBP) administers the schedule at the border and has the final say on how a given product is classified.

How an HTS Code Is Structured

An HTS code reads left to right, moving from broad to specific. The schedule is organized into chapters, and each chapter breaks down into headings, subheadings, and U.S.-specific lines.

The international portion runs through six digits and covers HS chapters 1–97. The United States then adds the 8-digit rate lines that carry the actual duty rate, plus a 10-digit statistical suffix used for trade data. The U.S. also keeps two domestic-only chapters: Chapter 98 for special classification provisions and Chapter 99 for temporary measures, which is where additional or special duties are layered in.

How Classification Actually Works

You cannot simply pick the code that sounds closest. Classification follows the General Rules of Interpretation (GRI) — a binding, ordered set of rules at the front of the schedule — supplemented by the Additional U.S. Rules of Interpretation. In practice:

• Start with GRI 1: classify according to the terms of the headings and any relevant section or chapter notes. Most goods are resolved here.
• Work the levels in order — heading first, then subheading — choosing the most specific description that fits.
• Read the section and chapter notes. They are legal text and can include or exclude products you would otherwise expect to land in a heading.
• Apply the later GRIs (2 through 6) only when GRI 1 doesn’t resolve the goods — for mixtures, incomplete articles, sets, or competing headings.

Classification is a question of what the product is — distinct from where it is from. Origin is determined separately under country of origin marking rules, and both feed into the duties and trade measures that ultimately apply.

Common Classification Mistakes

Most classification errors trace back to a few habits worth avoiding.

• Classifying by name, not by composition or function. The schedule often turns on material, use, or how an item is made — not its commercial name.
• Ignoring the notes. Section and chapter notes routinely move products out of the “obvious” heading.
• Using a stale code. The WCO revises the HS roughly every five years, and the USITC updates the HTSUS more often; a code that was right two years ago may not be today.
• Treating the 10-digit suffix as the duty line. The duty attaches at the 8-digit level — the statistical suffix does not change the rate.

CBP expects importers to exercise reasonable care in classification. A wrong code that understates duty can lead to additional duties owed plus penalties, so the standard is diligence, not guesswork. Complex goods — multifunction devices, software and technology, or assemblies like automotive parts — are where careful analysis pays off most.

When You’re Not Sure: Binding Rulings

When classification is genuinely close, you do not have to guess and hope. An importer can request a binding ruling from CBP before goods arrive. CBP issues a written determination you can rely on, and once issued it binds CBP at every U.S. port for that product. Searchable past rulings (CBP’s CROSS database) also show how the agency has treated similar goods. A binding ruling converts a judgment call into certainty — valuable when the duty difference between two codes is large or when you import the same product at volume. For the step-by-step approach to working a product through the schedule, see our guide to classifying goods for import.

Frequently Asked Questions

Who is responsible for assigning the right HTS code?

The importer of record is. You declare the classification to CBP, and CBP can agree, reclassify, or challenge it. You are expected to use reasonable care, which is why importers document their reasoning and request binding rulings when a code is unclear.

What is the difference between an HS code and an HTS code?

The HS code is the internationally standardized six-digit code administered by the WCO. The HTS code is the U.S. version, which keeps those six digits and adds U.S.-specific 8-digit rate lines and 10-digit statistical suffixes.

Where does the duty rate actually attach?

At the 8-digit level. The legal text of the HTSUS — including the duty rate — ends at eight digits. The final two digits (the 10-digit code) are for statistical reporting and do not change the rate.

Can I rely on a classification CBP gave me before?

Yes, if it was issued as a binding ruling. A binding ruling commits CBP to that classification for the identical product at all U.S. ports until it is modified or revoked.

Misclassification is one of the most common — and most expensive — import problems, because it compounds across every shipment. Reidel Law Firm helps importers classify goods, request binding rulings, and build defensible classification practices on flat-fee terms. Get an import compliance memo.