If you sell on Amazon, eBay or a retailer marketplace, you will be asked for a barcode number almost as soon as you create a listing. Get it right and nobody thinks about it again. Get it wrong and you can face blocked listings, products attached to the wrong page, or a costly relabelling job across your whole range.
This guide explains what GTINs are, how GS1 UK membership works and what it costs, why the cheap barcodes sold online cause problems, and when Amazon will let you list without one.
What a GTIN actually is
A GTIN (Global Trade Item Number) is the number that uniquely identifies a product. The barcode is simply the machine-readable picture of that number: the black and white lines a scanner reads. GS1 UK explains that a GTIN is usually 13 digits long in the UK and most of the world, 12 digits in the USA and Canada, and occasionally 8 digits for very small products.
You will see several names used for closely related things:
- GTIN: the umbrella term for the product number itself.
- EAN (European Article Number): the standard barcode carrying a 13-digit GTIN, used on most products sold in the UK and everywhere outside the USA and Canada.
- UPC (Universal Product Code): the barcode carrying a 12-digit GTIN, common in the USA and Canada.
- ISBN: the identifier used for books.
Marketplaces use these numbers to organise their catalogues. When two sellers list the same product, the GTIN is how the marketplace knows it is the same item. That is why accuracy matters so much. GS1 UK points out that if your product is given the same identifier as another product, it causes a data conflict in the marketplace's catalogue.
EAN vs UPC: does it matter which you use?
For most UK sellers, no. GS1 UK says both the 12-digit UPC and the 13-digit EAN are part of the same GS1 system of international standards, so both are accepted globally. If you join GS1 UK, you will be working with 13-digit numbers, and these work on Amazon.co.uk, eBay and other UK marketplaces. Amazon's own help pages note that an EAN or UPC is the identifier most commonly used to create or match product pages.
What matters far more than the format is where the number came from.
GS1 UK membership: how it works and what it costs
GS1 is the not-for-profit organisation that runs the barcode system worldwide, and GS1 UK is its UK member organisation. When you join, you get a GS1 Company Prefix: a block of numbers registered to your business, from which you create a GTIN for each product.
Membership is priced by your company's annual turnover. Your GTINs are licensed to you as part of that membership, and you renew each year to keep using them. At the time of writing (October 2026), the annual fees are:
| Annual turnover | Annual fee (excluding VAT) | GTINs included |
|---|---|---|
| Up to £99,999 | £50 | 10 |
| £100,000 to £499,999 | £100 | 100 |
| £500,000 to £999,999 | £130 | 1,000 |
| £1,000,000 to £9,999,999 | £200 | 1,000 |
| £10,000,000 to £49,999,999 | £450 | 10,000 |
| £50,000,000 to £249,999,999 | £1,750 | 10,000 |
| £250,000,000 to £999,999,999 | £3,250 | 100,000 |
| Over £1,000,000,000 | £4,250 | 100,000 |
Source: GS1 UK. Since 1 April 2025, GS1 UK has included free barcode images on all plans and lets members add more numbers as their range grows. Its published price table does not list a separate joining fee, but check the current terms when you sign up, because pricing can change.
How many GTINs do you need?
More than most people expect. GS1's GTIN Management Standard treats each style, colour and size of a product as a unique product with its own GTIN. Its own example is a T-shirt line in sizes S, M, L and XL, where every size and colour combination gets a separate number.
Bundles need their own GTIN too. GS1 calls a fixed set of items sold together a "predefined assortment", and if you change what goes into it, you need a new GTIN.
Count before you choose a plan. A range of 40 products, each in three colours, needs 120 GTINs, not 40. On the smallest GS1 UK band you get 10 numbers included, so you would need to add more as you go.
Why cheap resold barcodes cause problems
Search for "buy barcodes" and you will find websites selling EANs for a few pounds each, with no annual fee. It is tempting when you are starting out. Here is the catch.
The numbers sold by resellers were originally issued by GS1 to another company. GS1 UK warns that these barcodes may have had previous owners, so the number is still tied to the original brand or product; that major retailers and marketplaces such as Amazon may not accept them; and that you may run into number clashes with your trading partners.
Amazon is explicit about this. It verifies product identifiers by checking the GS1 database, and EANs or UPCs that do not match GS1's information are treated as invalid. Amazon tells sellers to get identifiers directly from GS1, not from third parties selling EAN and UPC licences, and warns that using incorrect or purchased codes can lead to your ASIN creation or selling privileges being temporarily or permanently removed. (An ASIN is Amazon's own product code, the identifier behind every product page.)
The trouble often surfaces months later rather than on day one:
- Listings get matched to the wrong product. If the number already belongs to something else in the catalogue, your listing can attach itself to a page that is not yours.
- Listings are removed. Amazon says invalid EANs or UPCs will be removed.
- Retailers check too. GS1 UK says only numbers allocated by GS1 member organisations can be searched and verified on its global database. If you later pitch to a retailer or join a retailer marketplace, borrowed numbers can hold you back.
- Fixing it is expensive. Swapping numbers means new labels or packaging, new listings, and the risk of losing sales history and reviews attached to the old ones.
You can check any number on GS1's Verified by GS1 service, which shows whether it is authentic and who it is allocated to. If you bought barcodes from a reseller in the past, check them now rather than waiting for a listing to be blocked.
When Amazon lets you list without a GTIN
Amazon offers a product ID exemption, usually called a GTIN exemption, for some products. According to Amazon's UK help pages, you can apply if you are selling:
- private-label or handmade products
- products you manufacture, brand or publish without barcodes
- parts that do not have a product ID, such as some car parts or phone accessories
- bundles, such as a belt and wallet set
- generic, unbranded products
You cannot get an exemption if the product already has a GS1 barcode or another product ID, if it is already in the Amazon catalogue, or if the brand is one Amazon requires a barcode for.
What Amazon needs to see
For branded products, the application is about proving the brand is real and permanent. Amazon asks for clear, real-world photos of all six sides of the product and its packaging: front, back, left, right, top and bottom. The brand name must be permanently affixed, for example printed, embossed, on a sewn-in label or on a permanent tag or nameplate. Removable stickers, digitally added logos and computer renderings are common reasons for rejection.
Truly generic products with no brand name are approved automatically. Branded applications are usually decided within 48 hours, and Amazon advises waiting 30 minutes after approval before listing.
Exemptions are granted by category and by store, not product by product. One approval for clothing covers future clothing items too, but if you sell in several Amazon stores you need an exemption in each one.
An exemption is not permanent cover. Amazon says it may expire exemptions for brands that later acquire GS1 barcodes. If you join GS1 down the line, plan to add the new GTINs to your listings.
Exemption or GS1: which is right for you?
An exemption suits handmade goods, small private-label runs and genuinely generic items sold only on Amazon. If you plan to sell on several marketplaces, wholesale to shops or join a retailer marketplace, GS1 numbers are usually the simpler long-term route because one number works everywhere. GS1 UK's own position is that a GS1 GTIN is needed to list with major retailers and marketplaces, and Amazon's exemption only covers Amazon.
eBay and other marketplaces
eBay asks for product identifiers such as brand, EAN or MPN (manufacturer part number) in many categories. Its item description policy does not allow you to enter "Does not apply", "unbranded" or "N/A" for a required identifier when the manufacturer has provided that information for the product. If your product genuinely has no barcode, say so. If it has one, use it.
If you are thinking about retailer marketplaces such as B&Q or Tesco, check their product data requirements before you start. Setting up proper GS1 numbers from the beginning is far easier than redoing your product data later. Our guide to UK retailer marketplaces explains how each one works.
A simple barcode checklist
- Decide whether you need GTINs at all. If you only sell handmade or unbranded goods on Amazon, an exemption may be enough for now.
- If you do need them, join GS1 UK directly and pick the band that matches your turnover.
- Assign one GTIN per variation (size, colour, pack size) and one per bundle.
- Keep a master spreadsheet linking each GTIN to its SKU (your own stock code), product name and variation, so the same number is never used twice.
- Check any older or bought-in barcodes on Verified by GS1.
- Print barcodes clearly on packaging or labels so warehouses and retailers can scan them.
If you would like a second pair of eyes on your product identifiers and listings, book a free 20-minute demo. We look at your products and the channels you sell on today.
Key takeaways
- A GTIN is the product number; EAN (13 digits) and UPC (12 digits) are barcode formats, and both work globally.
- GS1 UK membership is priced by turnover, from £50 a year plus VAT for businesses turning over up to £99,999, renewed annually.
- Every size, colour and bundle needs its own GTIN, so count your variations before choosing a plan.
- Amazon checks numbers against the GS1 database and treats resold or purchased codes that do not match as invalid.
- Amazon's GTIN exemption suits handmade, private-label and generic products, but it is category and store specific and only covers Amazon.