HTS Code vs HS Code: The Difference US Importers Actually Need to Know

If you import into the United States, you have probably seen the terms HS code and HTS code used interchangeably by freight forwarders, suppliers, and even software products. They are not interchangeable. The difference is small in digits and large in consequences: it decides which duty rate applies, whether trade-agreement benefits are available, and whether your customs entry is even valid.

The short version: HS is the international standard. HTS is the US implementation of it. Everything else follows from that.

What the HS Code Is

The Harmonized System (HS) is a global nomenclature maintained by the World Customs Organization (WCO). More than 200 customs administrations use it, and the first six digits of a product’s classification are the same everywhere. A cotton t-shirt is 6109.10 whether it clears customs in Los Angeles, Rotterdam, or Yokohama.

The HS is structured as:

Level	Digits	Example
Chapter	2	61 (knitted or crocheted apparel)
Heading	4	6109 (t-shirts, singlets, vests, knitted)
Subheading	6	6109.10 (of cotton)

The six-digit level is where international harmonization ends. Each country then extends the number for its own tariff and statistics.

What the HTS Code Is

The Harmonized Tariff Schedule (HTS) is the United States’ legal tariff schedule, maintained by the US International Trade Commission (USITC). It takes the six international digits and adds four more:

8-digit subheadings carry the actual duty rate lines. This is the level you declare for duty purposes.
10-digit statistical suffixes exist for trade-data collection. This is the level required on the customs entry.

So for our cotton t-shirt, the HTS line looks like 6109.10.0012, where the final digits split cotton t-shirts into statistical categories such as men’s and boys’. Same first six digits as the rest of the world; the last four are US-specific.

The practical rule: when someone in the US supply chain asks for “the HS code,” they almost always need the full 10-digit HTS number.

Why the Difference Matters for Duty

Duty rates attach at the 8-digit level, and additional trade measures attach at the 10-digit level. Two examples worth internalizing:

Trade agreements. The HTS has three rate columns: General (the standard MFN rate), Special (preferential rates for FTA partners and preference programs), and Column 2 (for countries without normal trade relations). Whether you can use a Special rate depends on the 8-digit line plus origin documentation. A six-digit code alone cannot tell you this.

Additional tariffs. Section 301 duties on China, Section 232 steel and aluminum measures, and other surcharges are applied to specific 10-digit HTS lines through Chapter 99 provisions. Two products that share a 6-digit subheading can carry completely different additional-duty burdens at the 10-digit level.

A Common and Expensive Mistake

Many sellers copy the 6-digit code from a supplier’s commercial invoice, or accept a code quoted in a factory’s product listing, and file it as-is. Sometimes the code is simply wrong. Often it is right at the heading level but imprecise below it, which is where the US duty rate actually lives.

The correction loop is boring but effective:

Start from the product’s objective characteristics: material, function, composition, and use.
Find the right heading, then walk down the subheadings, reading each level’s full text.
Check the duty rate, units of quantity, and any Chapter 99 flags on the specific 10-digit line.
When two candidate codes compete, apply the classification rules (GRI) rather than picking the cheaper one.

You can run this loop faster with our HS Code Finder, which grounds its answers in the official HTS and shows you the candidate headings it considered. For shipments where the money matters, confirm the final number with a licensed customs broker or a CBP binding ruling.

Quick Reference

Question	Answer
Are the first 6 digits the same worldwide?	Yes, that is the HS standard
How many digits does CBP want on the entry?	10 (full HTS)
Where is the duty rate?	The 8-digit HTS subheading line
Who maintains the HTS?	USITC, updated throughout the year
Who maintains the HS?	World Customs Organization, revised every 5 years

This article is general information, not legal advice. Confirm classifications on specific goods with a licensed customs broker or CBP.