HS codes and duty rates: how they relate

Written by James F. Kollie, Jr. · Published 9 September 2026 · Reviewed 9 September 2026 · 8 min read

Classification and rate are two different jobs

Classification answers "what is this product, in tariff terms?". Rate-setting answers "what does this country charge on that product, arriving from that origin, today?". The first is largely international and stable. The second is entirely national and changes.

This is why no honest tool can hand you a duty rate from a six-digit code alone, and why TrueCost does not try to. We help you identify and record the code and the rate you have verified; we never invent the rate.

What the digits mean

• 2 digits — chapter. The broad family of goods. Chapter 27, for example, covers mineral fuels and oils.
• 4 digits — heading. A narrower product group within the chapter.
• 6 digits — subheading. The most detailed level agreed internationally under the Harmonized System, maintained by the World Customs Organization and used by most trading nations. Descriptions at this level are internationally comparable.
• 8, 10 or more digits — national extensions. Each country (or customs union) subdivides the six-digit subheading for its own tariff, statistical and policy needs. The wording, the number of digits and the rates all belong to that country.

So 8471.30 means the same category of goods in every HS country. The eight- or ten-digit line your destination assesses under, and the rate attached to it, do not exist at the international level at all.

Read the World Customs Organization's overview of the Harmonized System for the authoritative description of the structure and its legal notes.

How TrueCost handles codes

When you enter a code, the calculator normalises it and looks up the official international description for the chapter, heading and six-digit subheading, sourced from the UN Statistics Division HS 2022 reference. It shows the source and revision alongside the result, and it distinguishes:

• the international HS6 description, which is authoritative for classification;
• any national extension digits you enter, which the tool records but cannot validate for you;
• your own editable destination tariff description, source and date — the wording your destination actually uses, which you can paste in and keep with the costing.

The same code also drives an advisory hazardous-goods flag, which tells you when a classification commonly involves dangerous-goods handling. That flag is a prompt to check a safety data sheet and UN classification, never a determination.

What sets the rate

1. The national tariff line. The destination's own schedule, at full digit length, for the goods as classified.
2. Origin. Where the goods were produced, not where they shipped from. A free trade agreement, regional customs union or preference scheme can reduce or remove duty entirely — but only against valid origin documentation.
3. Trade measures. Anti-dumping duty, countervailing duty, safeguards, quotas and temporary suspensions attach to specific products and origins.
4. Product-specific charges. Excise, environmental levies and other border charges may apply on top of duty, sometimes on a per-unit basis.
5. End use and exemptions. Manufacturing inputs, agricultural equipment, medical goods and investment-incentive imports are commonly treated differently.
6. Date. Tariffs change with budgets, phase-downs and trade agreements.

A verification workflow that holds up

1. Classify from the product's objective characteristics — material, function, state and packing — using the HS legal notes, not marketing language.
2. Confirm the six-digit subheading, then find the destination's full national line in that country's own published tariff schedule.
3. Record the rate, the levies attached to the line, the schedule version and the date you read it.
4. Check origin evidence and whether a preference applies. If it does, note the certificate or declaration required.
5. Have a licensed clearing agent or customs broker confirm the line in writing before you place the order. Where the stakes are high, ask the destination authority for a binding or advance ruling.
6. After clearance, compare the line on the assessment notice with the one you used. Any difference is worth understanding immediately, not next shipment.

Traps

• Reusing a supplier's export code. Exporters classify for their own country and their own incentives.
• Assuming eight-digit codes match across countries because the first six digits do.
• Taking a rate from a third-party lookup with no version or date. If you cannot cite where a rate came from, you cannot defend the costing.
• Confusing shipment origin with country of origin when claiming a preference.
• Forgetting that the duty you calculate usually raises the tax base as well — see how the import VAT and GST base is built.

Once you have a verified line and rate, enter them in the free calculator and the rest of the sequence follows the method in the landed cost guide.

How we calculate and verify this

Every figure on this page is produced by the same calculation engine the free calculator and TrueCost Pro use, applied in the sequence set out in our calculation methodology. We publish no duty, excise, levy or tax rates of our own: rates, bases and exemptions are entered by you, and country presets are explanatory starting points that record where they came from and when they were last reviewed.

Results are estimates. This guide explains general method, not the law of any country. Confirm your tariff line, rate, tax base and exemptions with the destination customs authority or a licensed clearing agent before you commit to a purchase or a price. Nothing here is customs, tax or legal advice. If you find something wrong, tell us and we will correct it.