GTIN

A GTIN (Global Trade Item Number) is the globally unique number that identifies a product in trade. It is the umbrella term for the numbering systems most people know by other names: UPC in North America, EAN in Europe and most of the world, plus ISBN for books and a longer format used for cases and cartons. The barcode printed on a package is simply a machine-readable version of the GTIN underneath it.

The defining feature is that it is not yours to make up. GTINs are issued through GS1, the global standards body, which licenses a company prefix to each business and lets that business assign numbers within its own prefix range. That licensing model is what makes the number genuinely unique worldwide rather than merely unique within one company's systems.

The GTIN formats

A 12-digit UPC and a 13-digit EAN can describe the same product, since a UPC is effectively a GTIN-13 with a leading zero. Systems that store them in different lengths without normalising are a recurring source of mismatches.

GTIN and SKU are not the same thing

This is the confusion worth clearing up, because both are product numbers and both appear in the same spreadsheets. A SKU is internal, invented by you, and meaningful only inside your own business. A GTIN is external, issued through GS1, and means the same thing to every retailer and marketplace in the world.

Every sellable variant needs its own GTIN, on the same logic as SKUs. A shirt in three colours and four sizes is twelve distinct products in trade terms, and twelve GTINs. Reusing one number across variants breaks the listings that depend on it.

Why marketplaces keep asking for one

Marketplaces use the GTIN to work out whether your product already exists in their catalogue. Supplying it is how your offer attaches to the right product page rather than creating a duplicate listing, which is why Amazon and most other marketplaces treat it as a required field for new listings.

They also validate it. Marketplaces increasingly check submitted numbers against the GS1 database to confirm the prefix genuinely belongs to the seller claiming it, which is what makes resold or second-hand barcodes a real problem rather than a technicality.

What brands get wrong with GTINs

• Buying cheap barcodes from resellers. Numbers sold outside GS1 are registered to whoever originally licensed that prefix, not to you. Marketplace validation catches this, and the listing gets blocked after the product is already made.
• Reusing a GTIN across variants. Each sellable variant needs its own. Sharing one across sizes or colours produces listings that cannot be told apart in any system downstream.
• Recycling numbers from discontinued products. GS1 rules restrict how soon a GTIN can be reassigned, and old data lingers in retailer catalogues long after you have moved on.
• Leaving it until launch. Getting a GS1 prefix takes time and carries an ongoing licence cost, and packaging artwork needs the barcode before it goes to print.

FAQ

What is the difference between a GTIN and a UPC?
UPC is a type of GTIN. GTIN is the umbrella term covering UPC (12 digits), EAN (13 digits), and the 8 and 14 digit formats. Asking for a UPC and asking for a GTIN-12 is the same request.

Is a GTIN the same as a SKU?
No. A SKU is your own internal code, invented by you and meaningful only within your business. A GTIN is issued through GS1 and identifies the product identically to every retailer worldwide. Products normally carry both.

Can I create my own GTIN?
Not legitimately. GTINs come from a GS1 company prefix licensed to your business. Numbers bought from resellers remain registered to the original licensee, and marketplace validation against the GS1 database will usually reject them.

Product data done properly is what keeps listings live across every marketplace you sell on. eBrands manages catalogue setup and listing operations as part of running channels for brands. See how product listings are managed across marketplaces.