HS codes 101: what UK sellers need to know for US shipping

What an HS code actually is

An HS code (Harmonized System code) is a six-to-ten-digit number that classifies your product for customs. The first six digits are an international standard maintained by the World Customs Organization; the US extends those six digits to ten in its own Harmonized Tariff Schedule (HTS) to specify the exact duty rate. Almost every country uses the same first six digits, then adds its own national sub-headings on the end. That’s it. There’s no mystery.

For a UK seller shipping to the US, the HS code on your commercial invoice tells US Customs and Border Protection (CBP) two things:

1. What the product is, so they can decide whether it’s allowed in at all (most products are; some — alcohol, firearms, certain herbal supplements — need permits).
2. The duty rate that applies, calculated as a percentage of the declared value.

The duty rate is the bit that affects your margin. A cotton T-shirt declared as HS 6109.10.00 attracts ~16.5% duty. The same T-shirt mis-classified as 6105.10.00 (men’s shirts, knitted) attracts ~19.7%. A £40 declared value, 100 parcels a month — that’s £150 of avoidable duty cost from a single wrong classification, every month.

The structure of an HS code

Take HS code 6109.10.00.10. Here’s what each pair of digits means:

• 61 — Chapter: Articles of apparel and clothing accessories, knitted or crocheted.
• 09 — Heading: T-shirts, singlets and other vests, knitted or crocheted.
• 10 — Sub-heading: Of cotton.
• 00.10 — US national-level extensions: Men’s or boys’.

The first six digits (6109.10) are the same in the UK and in the US — that part is the WCO standard. The remaining four digits (00.10) are US-specific. CBP only cares about the full ten-digit code on the commercial invoice. If you give them six, they assume the worst-case duty rate in the sub-heading and bill accordingly.

Where to look them up

For UK sellers shipping to the US, only the US Harmonized Tariff Schedule matters for the duty calculation. The official source is:

• hts.usitc.gov — the US International Trade Commission’s HTS online. Free, searchable, authoritative. Cluttered interface but it’s the actual government source CBP uses.
• rulings.cbp.gov — CBP’s cross-rulings database. If you’re unsure how a borderline product classifies, search here for past rulings on similar items. CBP rulings are binding precedent for that product.

What you should not rely on:

• Random aggregator sites that haven’t been updated since 2023. The HTS is reissued twice a year. Use the official USITC source or a tool that pulls from it.
• ChatGPT, Claude or Gemini outputs without verification. AI tools are confidently wrong about HS codes more often than they’re right — they generalise from outdated training data. Always cross-check against USITC.
• A competitor’s HS code on their packing slip. They might have it wrong. They probably do.

At TradeWind we run our own HS-code suggester at the booking step. It looks up the official USITC tables, suggests the closest match to your contents description, and shows the resulting duty rate before you commit. If you’re unsure, that’s the safest starting point.

The four mistakes UK sellers make

In four years of running customs for a UK 3PL and now at TradeWind, these are the four mistakes I see again and again.

Mistake 1: Picking the lowest-rate code instead of the right code

“My HS code lookup gave me two options for this leather wallet — one at 9% and one at 4.5%. I’ll go with the 4.5%.”

This is customs fraud. Pick the code that accurately describes the product, not the one with the lower rate. CBP cross-references the declared HS code against your product description and the commercial invoice; if they don’t match, the parcel gets pulled. Repeat mis-classification triggers compliance audits and the penalty scales with parcel volume.

If two codes genuinely both apply (the substantial-transformation rules sometimes create real ambiguity for assembled or multi-material products), the choice is yours — but document why you picked the one you picked, so you can defend it.

Mistake 2: Using “handmade” as a code

There is no HS code for “handmade”. HS codes describe what an item physically is, not how it was made:

• Handmade silver necklace → HS 7113.11.50 (jewellery of silver, worked, with precious metal). Same code as a machine-made one.
• Handmade cotton scarf → HS 6214.20.00 (scarves, of cotton). Same code as a Primark scarf.
• Handmade wooden bowl → HS 4419.12.00 (wooden tableware, decorative). Same code as an IKEA bowl.

The handmade label belongs in your marketing, not on your customs form. CBP doesn’t care that the buyer paid extra because it’s artisan; CBP cares what tariff schedule the item physically falls under.

Mistake 3: Vague item descriptions on the commercial invoice

The HS code is one part of the picture. The text description of the contents on the commercial invoice is the other. CBP officers spot-check parcels by reading the description, then cross-reference to the declared HS code. If they don’t match, the parcel gets pulled.

Bad: “Clothing”, “Gift”, “Sample”, “Accessories”, “Personal items”.

Good: “Men’s cotton T-shirt, size L, navy, 1 unit”, “Ceramic mug, hand-thrown, 350ml, 1 unit”, “Wooden bookshelf sign, oak, with ‘Reader’ text engraved, 1 unit”.

The good descriptions take ten extra seconds to write and they prevent ~95% of avoidable customs holds. TradeWind auto-generates the commercial invoice from your booking inputs, which is one reason the parcels we ship clear faster than industry average — but you still need to give us specific contents.

Mistake 4: Wrong country of manufacture

This is the field UK sellers get wrong most often, especially Etsy resellers and dropshippers. Country of manufacture is where the product was physically made or substantially transformed — not where you bought it from, not where it shipped from.

• You make a candle in your Sheffield studio → country of manufacture is “United Kingdom”. Easy.
• You buy plain canvas bags from a Chinese supplier in bulk, print a design on them in your UK workshop, and resell them → if the printing is substantial enough to count as a transformation (case law is patchy here), country of manufacture can be UK; if it’s just decoration, it’s China. CBP defaults to China if challenged.
• You dropship from a Chinese supplier directly to a US buyer → country of manufacture is China, period. It doesn’t matter that the order routed through your UK Shopify storefront.

The reciprocal-tariff regime under EO 14324 assigns different rates by origin country. UK-origin goods get the UK reciprocal floor (10%). Chinese-origin goods get a substantially higher reciprocal rate. CBP audits cross-reference declared origin against the bill of materials in your supplier records — getting this wrong costs more than getting it right, when they catch you.

Common HS codes for UK ecommerce

These come up over and over in the UK→US ecommerce flow. Useful starting points — verify your specific product against the USITC tables.

A few patterns worth noticing:

• Books, soap, candles, and original art prints are all duty-free. If your product mix lands here, US import duty isn’t going to be a big line item for you. Lucky.
• Apparel and footwear are the worst categories for UK→US duty — rates often 15-25%, sometimes up to 37.5% for footwear with specific construction. If you sell knitted cotton clothing, your effective duty rate is typically 16-19%, which materially affects US pricing decisions.
• Jewellery is moderate — most types land at 5-6.5%, which is manageable. Adjust pricing by ~7% on US-targeted listings to absorb.
• Wood, ceramics, glass sit in the 3-10% range. Painful but workable.

Always confirm against USITC. The above is a 2026 snapshot — rates shift quarterly.

When to get a binding ruling

If you ship more than 500 parcels a month of a single SKU and the HS code classification has genuine ambiguity, request a CBP binding ruling at rulings.cbp.gov. It’s free, takes 30-90 days, and gives you a legal certificate that the code you’ve declared is correct. Binding rulings protect you from compliance audits and are worth having if your business depends on a specific code being defensible.

For small-volume sellers it’s not worth the time. Pick the code that most accurately describes the product, document why, and move on.

In summary

HS codes are simpler than they look:

1. Look up the code that accurately describes your product on hts.usitc.gov.
2. Be specific in your commercial invoice description — describe what the item physically is, not what it’s for.
3. Get the country of manufacture honest — where it was physically made, not where it shipped from.
4. Use TradeWind’s HS code lookup at booking or verify against USITC directly if you’re shipping a new product category.

Get those four things right and 99% of UK→US parcels clear customs in hours rather than days. Get any of them wrong and you’ll find out the hard way at the border.

Questions about a specific product? Email support@tradewind.express with the contents description and we’ll suggest the most likely HS code from USITC. It’s the kind of work we’d rather get right at the booking step than fight about at the border.