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Compliance6 min readUpdated

HS codes explained: how to classify a product correctly

An HS code is the number customs uses to classify a product and set its duty. The first six digits come from the World Customs Organization's Harmonized System and are shared by most of the world's customs administrations; each country then adds its own digits, such as the EU's 8-digit CN code or the US 10-digit HTS number. You classify by applying the six General Interpretative Rules in order, starting with the wording of the headings and the legal notes.

AnirudhFounder and Director, SourceSquid · 15 years sourcing in India and China

Key takeaways

  • The first six digits (chapter, heading, subheading) are international. National digits and duty rates are set by each country.
  • Classify with the General Interpretative Rules (GRIs), in order. GRI 1, the heading text and legal notes, settles most cases.
  • A product named in a specific heading goes there, even if it is made of a material with its own chapter.
  • The code decides the duty rate, so a wrong code changes your landed cost and can lead to duty demands later.
  • When in doubt, apply for a binding ruling: BTI in the EU, an Advance Tariff Ruling in the UK, a CBP ruling in the US.
On this page7 sections
  1. How an HS code is built
  2. The six General Interpretative Rules
  3. Worked example: a vacuum-insulated bottle
  4. A practical classification method
  5. Common classification traps
  6. When to get a binding ruling
  7. Why the code matters beyond duty

How an HS code is built

The Harmonized System, maintained by the World Customs Organization (WCO), organises all goods into 21 sections and 97 chapters, of which chapter 77 is reserved for future use. Each code narrows down in pairs of digits:

Digits Level Example: 9617.00
2 Chapter 96: Miscellaneous manufactured articles
4 Heading 9617: Vacuum flasks and other vacuum vessels, complete; parts thereof other than glass inners
6 Subheading 9617.00

These six digits are shared internationally. Beyond them, each country or customs union adds national digits for its own duty rates and statistics:

Market Code used for import Length
European Union Combined Nomenclature (CN), plus TARIC codes for measures 8 digits (CN), 10 (TARIC)
United States Harmonized Tariff Schedule (HTSUS) 8-digit tariff line, 10-digit statistical number
United Kingdom UK Global Tariff commodity code 10 digits for import
India ITC(HS) 8 digits

The practical consequence: an Indian or Chinese exporter’s code should match yours at six digits, but the national digits, and the duty, belong to the import country. Always classify to the importing country’s full code.

The six General Interpretative Rules

Classification is a legal exercise, governed by the General Interpretative Rules (GRIs) at the front of every tariff. They apply in order: you only move to the next rule when the previous one cannot decide.

Rule What it says
GRI 1 Classify by the terms of the headings and any section or chapter notes. Titles of sections and chapters are for reference only.
GRI 2(a) An incomplete, unfinished, unassembled or disassembled article is classified as the finished article if it has the finished article’s essential character.
GRI 2(b) A reference to a material includes mixtures and combinations with other materials; such goods go on to GRI 3.
GRI 3(a) When two headings could apply, the most specific description wins.
GRI 3(b) Mixtures, composite goods and sets for retail sale are classified by the component that gives them their essential character.
GRI 3(c) If still undecided, take the heading that comes 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 and containers made for an article, and normal packing, are classified with the goods.
GRI 6 Subheadings are decided by the same rules, comparing only subheadings at the same level.

Most products are settled at GRI 1. The legal notes are where the answers hide: they include and exclude goods from chapters and headings, and they take precedence over your instinct about what a product “is”.

Worked example: a vacuum-insulated bottle

Product. A 750 ml double-walled stainless steel drinks bottle with a vacuum between the walls and a polypropylene screw lid.

First instinct. It is a steel household article, so Chapter 73, heading 7323: table, kitchen or other household articles of iron or steel. In the US, 7323.93.00 (of stainless steel) carries a general rate of 2%.

GRI 1 says otherwise. Heading 9617 names “vacuum flasks and other vacuum vessels, complete”. And Note 1 to Section XV, which covers base metals and Chapter 73, excludes articles of Chapter 96. The bottle is a vacuum vessel named by heading 9617, so it cannot be classified in 7323.

GRI 6 and national digits. At six digits the code is 9617.00. In the 2026 US HTS the subheadings split by capacity: 9617.00.10, “having a capacity not exceeding 1 liter”, with a general rate of 7.2%.

Why it matters. On goods with a customs value of $40,000, the difference between 2% and 7.2% is $2,080 in general duty before any additional duties. Using the steel heading would understate the duty, and customs can reclassify and claim the difference later.

You can check both lines, and search the full 2026 US tariff, with the HS code finder.

A practical classification method

  1. Describe the product precisely. What it is, what it is made of (with percentages for mixtures), how it works, what it is used for, and how it is presented for sale (single, set, kit).
  2. Find candidate headings. Search by function and by material. Note every heading that could plausibly apply.
  3. Read the section and chapter notes for each candidate. Many candidates drop out here.
  4. Apply the GRIs in order, and write down which rule decided it.
  5. Go down to national digits with GRI 6, comparing subheadings at the same level.
  6. Check rulings. Search the EU’s EBTI database, the US CROSS database or UK rulings for similar products.
  7. Record your reasoning. A short classification note with photos protects you if customs asks later.

Common classification traps

Most errors come from a handful of situations. Watch for these:

  • Classifying by material when a heading names the function. As in the bottle example, a specific heading can take a product out of its material chapter.
  • Sets and kits. Goods put up in sets for retail sale are classified by the item that gives the set its essential character (GRI 3(b)). A gift set of a mug and a spoon is not two codes.
  • Unassembled goods. A flat-packed chair is classified as a chair, not as its panels (GRI 2(a)).
  • Parts and accessories. Many headings cover “parts”, but section and chapter notes often send general-purpose parts, such as screws, bolts and springs, to their own headings.
  • Textile blends. Textile classification depends on fibre composition by weight. Get exact percentages from the supplier, not “cotton rich”.
  • Copying the supplier’s code. Export codes are chosen for export statistics and incentives. Check the first six digits and classify the rest yourself.

When to get a binding ruling

For high-value lines, new products or genuinely unclear cases, a binding ruling removes the doubt.

  • EU: Binding Tariff Information (BTI), issued by a member state’s customs authority and binding across the EU, generally valid for three years.
  • UK: Advance Tariff Ruling from HMRC, generally valid for three years.
  • US: A ruling letter from CBP, requested before import; published rulings are searchable in CROSS.

Why the code matters beyond duty

Your HS code also decides which other rules apply: anti-dumping duties, import licences, product safety regimes, and EU measures such as the Carbon Border Adjustment Mechanism, which covers goods by CN code. See CBAM for importers and Indian exporters. And because the code sets the duty rate, it feeds straight into your landed cost.

Free tools for this guide

Sources

  1. World Customs Organization: What is the Harmonized System?www.wcoomd.org/en/topics/nomenclature/overview/what-is-the-harmonized-system.aspx
  2. WCO: General Rules for the Interpretation of the Harmonized Systemwww.wcoomd.org/-/media/wco/public/global/pdf/topics/nomenclature/instruments-and-tools/hs-interpretation-general-rules/0001_2012e_gir.pdf?la=en
  3. US International Trade Commission: Harmonized Tariff Schedule (2026)hts.usitc.gov
  4. European Commission: EU Binding Tariff Information (BTI)taxation-customs.ec.europa.eu/customs/common-customs-tariff-cct/tariff-classification-goods/eu-binding-tariff-information-bti_en
  5. GOV.UK: apply for an Advance Tariff Rulingwww.gov.uk/guidance/apply-for-an-advance-tariff-ruling
  6. US CBP: Customs Rulings Online Search System (CROSS)rulings.cbp.gov

Checked on 28 September 2026. Rules and rates change: confirm against the official text before you act. This guide is general information, not legal or tax advice.

Written by

Anirudh

15 years in sourcing, vendor development and quality across India and China. MBA in Operations and Supply Chain Management and Lean Six Sigma Black Belt. Founder of SourceSquid, with offices in Bengaluru and Ningbo.

HS codes: questions

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What is an HS code?

An HS code is a product classification number from the Harmonized System maintained by the World Customs Organization. The first six digits are shared by most countries; each country adds national digits to set duty rates and collect statistics.

How many digits does an HS code have?

The international HS code has six digits. The EU Combined Nomenclature uses eight, the EU's TARIC adds two more for measures, the US HTS uses an 8-digit tariff line with a 10-digit statistical suffix, and India's ITC(HS) uses eight.

Who is responsible for the HS code on an import?

The importer, or the declarant acting for the importer, is responsible for the classification on the customs declaration. Suppliers and forwarders often suggest codes, but the liability for a wrong code and any unpaid duty stays with the importer.

Can the exporter's HS code be used for import?

The first six digits should match, because both countries use the same Harmonized System. The national digits will differ, so always classify to the import country's full code, and check the six digits rather than copying them.

What is a binding tariff ruling?

It is a written classification decision from customs for a specific product, binding on customs and the holder. In the EU it is Binding Tariff Information (BTI), in the UK an Advance Tariff Ruling, both generally valid for three years, and in the US a CBP ruling letter.

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