What an HTS code is
An HTS code is the ten-digit number that classifies an imported product in the Harmonized Tariff Schedule of the United States (HTSUS), and that classification sets the duty rate, the statistical reporting and most of the agency requirements that attach to the entry. Every formal U.S. entry of goods from China carries at least one of these numbers, and usually several.
The HTSUS is published and maintained by the U.S. International Trade Commission (USITC); the official searchable edition is at hts.usitc.gov. Its legal basis is 19 U.S.C. 1202, with maintenance and updates under 19 U.S.C. 3004–3005. The schedule is law, not guidance: the heading texts and the section and chapter notes are binding, and U.S. Customs and Border Protection (CBP) applies them at entry and again at liquidation (the point at which CBP finalizes the duty owed on an entry).
People use several names for the same thing. "HTS code", "HTSUS number", "tariff code" and "HS code" are often used interchangeably, but they are not identical. The HS (Harmonized System) is the six-digit international nomenclature maintained by the World Customs Organization. The HTSUS is the U.S. extension of it to ten digits. That difference is the source of one of the most common mistakes in China sourcing, covered below.
How the ten digits are built
An HTSUS number is read from left to right, each pair of digits narrowing the description. Only some of the digits change what you pay.
| Digits | Level | Set by | What it controls |
|---|---|---|---|
| 1–2 | Chapter | World Customs Organization (HS) | Broad product group |
| 1–4 | Heading | World Customs Organization (HS) | Product family within the chapter |
| 1–6 | Subheading | World Customs Organization (HS) | The international code shared by 200+ customs administrations |
| 7–8 | U.S. tariff rate line | United States (USITC) | The duty rate |
| 9–10 | Statistical suffix | United States (USITC/Census) | Trade statistics only; no effect on the rate |
Three consequences follow. First, an entry needs all ten digits; a six-digit code is not enough to file. Second, two products can share a six-digit subheading and still carry different U.S. duty rates at the eight-digit level. Third, the Section 301 China lists are defined by eight-digit HTSUS lines, so the eight-digit choice can decide whether a product carries a 25% list duty, a 7.5% list duty or none at all.
Two chapters sit outside the product chapters. Chapter 98 holds special classification provisions, such as U.S. goods returned and heading 9802 for articles assembled abroad from U.S. components. Chapter 99 holds temporary legislation and additional duties, which is where the China-specific tariffs live.
How classification is decided: the General Rules of Interpretation
Classification is not a keyword search. It follows the General Rules of Interpretation (GRIs), six rules printed at the front of the HTSUS, together with the Additional U.S. Rules of Interpretation. They are applied in order, and you move to the next rule only when the previous one does not resolve the product.
- GRI 1 — classify by the terms of the headings and the section and chapter notes. Most products are settled here. The notes override the heading text.
- GRI 2 — extends a heading to incomplete or unassembled articles that have the essential character of the finished article, and to mixtures and combinations of materials.
- GRI 3 — for goods that appear classifiable under two or more headings: the most specific description wins; failing that, the component that gives the essential character; failing that, the heading last in numerical order.
- GRI 4 — goods that fit no heading go to the heading for the goods they are most akin to.
- GRI 5 — cases, containers and packing materials.
- GRI 6 — applies the same logic at the subheading level, comparing only subheadings at the same level.
In practice the process runs in a fixed sequence. Identify the product's material, function and form. Read the relevant section and chapter notes, then the heading texts. Narrow to the six-digit subheading, then the eight-digit rate line and the ten-digit statistical suffix. A kitchen tool sold as a set with a storage case, or a molded part that could be read as a "part of" a machine or as an article of plastic, is the kind of product where GRI 3 and the chapter notes do the real work.
Reading the duty columns
Each eight-digit line in the HTSUS carries rate columns. For Chinese goods, the relevant one is easy to identify.
- General — the most-favored-nation (MFN, or normal trade relations) rate. This is the base rate that applies to products of China.
- Special — reduced or free rates under free trade agreements and preference programs, shown as program codes. China is not eligible for any of them.
- Column 2 — the higher statutory rates for countries whose normal trade relations have been withdrawn, such as Cuba and North Korea.
The General rate is only the first layer. For Chinese-origin goods it is almost never the whole duty, because additional duties attach through Chapter 99. The line also tells you which partner government agencies (PGAs, the other federal agencies with import rules, such as FDA, CPSC, EPA and USDA) may need data on the entry, which is a reason to confirm the code before the goods ship, not after.
Chapter 99: where Section 301 and other additional duties are reported
Additional duties on Chinese goods are not built into the General rate. They are reported on the entry as separate Chapter 99 HTS lines alongside the Chapter 1–97 classification. An entry that carries only the product classification under-declares duty.
As of October 2026, the main Chapter 99 lines that matter for China are these:
- Section 301 Lists 1–4A (the 2018–2019 China actions), reported under 9903.88 headings and keyed to specific eight-digit HTSUS lines; plus the 2024 four-year-review increases on named products such as semiconductors, solar cells and batteries.
- Section 301 forced-labor action: an additional 12.5% on products of China under HTS 9903.05.31, for goods entered on or after 12:01 a.m. ET 24 July 2026, with exemptions reported under 9903.05.85–9903.05.92, per CBP's CSMS #69326983 (the Cargo Systems Messaging Service bulletin CBP issued on 24 July 2026). Unlike Lists 1–4A, this action applies by country of origin, with HTS-defined exemptions.
- Section 232 lines for steel, aluminum, copper, autos and other covered products, where the article falls within a proclamation.
CSMS #69326983 also sets the reporting order on the entry summary: Section 301 lines first, then Section 122, then Section 232, then Section 201, and then the Chapter 1–97 classification.
Chapter 99 also records duties that are no longer collected. IEEPA lines (9903.01 headings for the "fentanyl" and "reciprocal" duties) were added in 2025 and ceased to be collected on 24 February 2026, after the Supreme Court held in Learning Resources, Inc. v. Trump (20 February 2026) that IEEPA does not authorize tariffs. The Section 122 surcharge, reported under 9903.03.01, applied from 24 February to 24 July 2026 and has expired. Both still matter for refund and reliquidation work on entries from those periods.
The HTS code on the ISF, the entry and the Chinese export declaration
The same shipment carries classification numbers in three places, and they are not required to match at every digit.
- The Chinese export declaration uses China's own ten-digit customs code. Its first six digits are the HS subheading; digits seven to ten are Chinese national lines.
- The ISF (Importer Security Filing, the advance cargo data filed for ocean shipments before loading) requires the commodity HTSUS number to at least six digits under 19 CFR 149.3(a)(8). Where the ISF and entry are transmitted together, the ten-digit code is provided once (19 CFR 149.6). The rule text is in 19 CFR Part 149.
- The U.S. entry summary requires the full ten-digit HTSUS number plus any Chapter 99 lines.
U.S. export statistics use a fourth system, Schedule B, maintained by the Census Bureau, which shares the first six HS digits and differs at seven to ten. The practical rule is simple: the six-digit HS subheading is the only part that should correspond between the Chinese export declaration and the U.S. entry. A supplier's ten-digit code is a starting point for the conversation, not a U.S. classification.
Who is responsible, and how to get certainty
The importer of record (the party legally responsible for the entry) is responsible for the classification. 19 U.S.C. 1484 requires the importer to use "reasonable care" in classifying and valuing goods. That duty stays with the importer when a licensed customs broker prepares the entry and when a supplier proposes the code. Misclassification penalties under 19 U.S.C. 1592 scale by culpability: negligence, gross negligence or fraud. CBP can also reclassify at liquidation and bill the difference.
Where the classification is uncertain or the duty at stake is large, an importer can request a binding ruling from CBP under 19 CFR Part 177 before importing. Issued rulings are searchable in CBP's CROSS database (Customs Rulings Online Search System), and reading rulings on similar products is the standard way to test a proposed classification. A licensed customs broker or trade attorney should confirm a classification before a large or recurring entry; that is a description of how the process works, not a referral.
The schedule itself changes. The USITC publishes several HTSUS revisions a year, and classifications should be reviewed when it does. The World Customs Organization's next HS edition is expected to take effect on 1 January 2027, but a U.S. implementation notice had not been confirmed when this page was written. If it takes effect, U.S. ten-digit codes for amended headings will change and Section 301 list mappings will need to be re-concorded.
Common classification mistakes on China imports
- Using the supplier's Chinese export code as the U.S. code. Only the first six digits correspond.
- Choosing a code to minimize duty. The GRIs decide the classification, and the importer bears the reasonable-care liability, not the broker or supplier.
- Reading heading text and skipping the notes. Section and chapter notes are legally binding and override heading text.
- Leaving off Chapter 99 lines. An entry with only the Chapter 1–97 line under-declares Section 301 duty.
- Filing a six-digit code on the entry. The ISF accepts six digits; the entry requires ten.
- Never revisiting a classification. HTSUS revisions and new Chapter 99 actions, such as the 24 July 2026 forced-labor duty, change what a code costs.
Frequently asked questions
How many digits is an HTS code?
A U.S. HTS code has ten digits for entry purposes. The first six are the international Harmonized System subheading shared with other customs administrations, digits seven and eight are the U.S. tariff rate line that sets the duty rate, and digits nine and ten are a statistical suffix that has no effect on the rate. The ISF accepts six digits; the entry summary requires all ten.
Who decides the HTS code for my product?
The importer of record decides, and must use reasonable care under 19 U.S.C. 1484. A customs broker or supplier may propose a code, but the legal responsibility stays with the importer. CBP can reclassify at liquidation. For certainty before importing, an importer can request a binding ruling from CBP under 19 CFR Part 177 and can search earlier rulings in CBP's CROSS database.
Can I use the HS code my Chinese supplier gives me?
Only the first six digits. China's export declaration uses a ten-digit Chinese national code whose last four digits differ from the U.S. HTSUS. The six-digit HS subheading should correspond across both declarations, but the U.S. eight-digit rate line and ten-digit statistical suffix must be classified under the Harmonized Tariff Schedule of the United States and its rules of interpretation.
Where do Section 301 tariffs appear on an entry?
They appear as additional Chapter 99 lines reported with the product classification. Lists 1–4A are reported under 9903.88 headings, and the 12.5% forced-labor duty in force since 24 July 2026 is reported under 9903.05.31, per CBP CSMS #69326983. That bulletin sets the reporting order: Section 301 lines first, then Section 122, Section 232, Section 201, then the Chapter 1–97 code.
Does a different HTS code change the Section 301 tariff?
Yes, for Section 301 Lists 1–4A, because those lists are defined by eight-digit HTSUS lines. A product on List 3 carries an additional 25% and one on List 4A carries 7.5%. The 12.5% forced-labor duty in force since 24 July 2026 works differently: it applies to products of China generally, except for HTS-defined exemptions, including goods subject to Section 232.
Is the HTS code on the ISF the same as on the entry?
It should describe the same product, but the precision differs. The ISF requires the commodity HTSUS number to at least six digits under 19 CFR 149.3(a)(8), while the entry requires ten. When the ISF and entry are filed together, the ten-digit code is supplied once under 19 CFR 149.6. A mismatch between the two is a common filing error.