Every product crossing a border is assigned a number from the Harmonized Commodity Description and Coding System — the HS code. It is maintained by the World Customs Organization and used by customs authorities around the world, which means a cotton T-shirt is classified the same way in Lagos, Rotterdam and Houston, at least for its first six digits.
That shared number does a lot. It determines the duty rate, decides whether the goods need an import licence or permit, flags restricted items, and feeds the trade statistics governments publish. Get it wrong and you may overpay duty, underpay and face penalties, or have the shipment held while customs reclassifies it.
How a code is built
The system is a hierarchy that narrows from broad families of goods down to specific products. The first six digits are internationally harmonised; countries then add their own digits for tariff and statistical purposes.
| Level | Digits | Example | Meaning |
|---|---|---|---|
| Chapter | 2 | 61 | Articles of apparel, knitted or crocheted |
| Heading | 4 | 6109 | T-shirts, singlets and other vests, knitted |
| Subheading | 6 | 6109.10 | Of cotton |
| National tariff line | 8–10 | 6109.10.xx | Set by each country |
Because the national digits differ, the full code for the same product can differ between countries. The United States uses ten digits in its Harmonized Tariff Schedule; the European Union uses an eight-digit Combined Nomenclature, extended to ten for its TARIC tariff. The first six still match.
How to classify a product
- Describe it precisely first. Note what it is, what it is made of, how it works, and what it is used for. Classification follows from the description, not the other way round.
- Find the chapter. Start from the material or function. A leather handbag sits with leather goods, not with clothing.
- Narrow to the heading and subheading by reading the legal text, including the section and chapter notes — they often exclude goods you would expect to be included.
- Apply the General Interpretative Rules where a product could fit more than one heading. Under these rules, the most specific description wins, and composite goods are classified by the component that gives them their essential character.
- Look up the destination's national tariff for the final digits and the duty rate.
Mistakes that cost money
- Classifying by what a product is called rather than what it is. Marketing names carry no weight with customs.
- Reusing a code from a supplier or competitor without checking it. Their classification may be wrong, or may be correct only in their country.
- Ignoring the chapter notes. They routinely move goods between headings.
- Using an outdated code. The WCO revises the system periodically, and codes are split, merged or retired between editions.
- Splitting a set to chase a lower rate. Goods put up together for retail sale are often classified as a set, by their essential character.
Responsibility for the classification sits with the importer, even when a broker or forwarder prepared the entry. If you are not certain of a code, it is cheaper to confirm it before the goods ship than to correct it after a duty assessment.