An HS code and an HTS code are two halves of the same number. The HS code is the 6-digit code that the whole world shares, maintained by the World Customs Organization and used by more than 200 countries. The HTS code is the United States version: it keeps those first six digits, then adds four more to reach a 10-digit line that carries the actual US duty rate. So every HTS code contains an HS code, but not every HS code is an HTS code. When you import into the US, you file the 10-digit HTS number, not the 6-digit HS root.
HS code vs HTS code at a glance
| HS code | HTS code | |
|---|---|---|
| Full name | Harmonized System code | Harmonized Tariff Schedule of the United States code |
| Length | 6 digits | 10 digits (the same 6, plus 4 US digits) |
| Who maintains it | World Customs Organization | US International Trade Commission (USITC) |
| Where it is used | 200+ countries, as the shared base | United States imports only |
| Carries the duty rate? | No, it is a classification base | Yes, the 10-digit line sets the rate |
| What you file to US customs | Not on its own | The full 10-digit HTS number |
How the digits stack up
The clearest way to see the relationship is to read one code from left to right. Take a lithium-ion power bank, HTS 8507.60.0020:
- 85 is the chapter (electrical machinery). This is shared worldwide.
- 8507 is the heading (electric storage batteries). Shared worldwide.
- 8507.60 is the subheading (lithium-ion). This is the full 6-digit HS code, and a customs officer in Germany, Japan or Brazil would recognize it.
- 8507.60.00 is the 8-digit US tariff line, where the duty rate lives.
- 8507.60.0020 is the full 10-digit HTS number, whose last two digits are a statistical suffix for trade data.
The first six digits are the international HS code. The last four are the US-specific HTS extension. That is the entire difference, and it is why the two terms get used loosely as if they were the same thing. They overlap by six digits and diverge by four.
Why the last four digits are the ones that cost you money
Two products can share an identical 6-digit HS code and still owe different duty once you reach the 10-digit HTS line, because the US uses those extra digits to split a subheading by material, use or specification. The 6-digit HS code tells you what family a product is in; the 10-digit HTS code tells you what you actually pay. That is why quoting only the 6-digit code to a broker or a supplier is not enough for a US entry, and why a duty estimate is only as good as the full HTS number behind it. Once you have the 10-digit code, running it through an import duty calculator turns it into a real dollar figure.
When to use each one
Use the 6-digit HS code when you are talking to the rest of the world: an overseas supplier, a freight forwarder abroad, or an export declaration where the destination country will add its own national digits. Use the full 10-digit HTS code when you are importing into the United States, because that is what US Customs and Border Protection requires on the entry, and it is the number that determines your duty. Exporters leaving the US file a Schedule B number, which is a close cousin built on the same 6-digit HS base but designed for outbound statistics rather than duty.
The mistakes importers make with the two codes
- Filing only 6 digits. A US entry needs the full 10-digit HTS line. A 6-digit HS code is a starting point, not a filing.
- Assuming a supplier's HS code is your HTS code. An overseas supplier usually knows the 6-digit root and their own country's extension, not the US 10-digit line. Confirm the last four digits yourself.
- Copying a code across countries. The first six digits travel; the national digits do not. A code that is correct for the EU is only correct in the US up to the sixth digit.
- Ignoring the statistical suffix. The final two digits do not change the duty rate, but they do drive trade statistics and CBP expects the correct one.
A large share of these errors trace back to a vague product description. The material, function and construction are what decide the last four digits, so the same three details that pin down an HS code also decide the HTS line. For a specific product family, our category guides walk the common codes, for example the HS code for electronics and the HS code for furniture.
Keeping the paper trail for an audit
US Customs expects importers to use reasonable care and to keep records that show how a code was chosen. That means holding the commercial invoice, the classification rationale and the entry summary together, and being able to reconcile the duty and freight you paid against what actually left your account. When those charges are buried in a supplier's PDF statement, it helps to turn the statement into a clean spreadsheet before you match line items, so an audit request does not turn into a week of manual retyping. The stronger your records, the cheaper a customs review becomes.
The short version
HS code and HTS code are not rivals; they are nested. The HS code is the shared 6-digit international classification, and the HTS code is the US 10-digit version that adds four national digits and the duty rate on top. Talk to the world in HS digits, and file to US customs in the full HTS number. If you are not sure of the last four digits, describe the product on the HTS code lookup and let the classifier propose the full line, with a rationale you can keep on file.