What is GTIN?
GTIN, or global trade item number, is the standard identifier that uniquely names a product worldwide, covering the barcode formats such as UPC, EAN and ISBN.
Worked example, not a result
A catalogue that is half resold and half own brand
Say a store lists 850 products. Around 715 of them are branded items bought from other manufacturers, and each one has a barcode on the box: a UPC of 12 digits in North America, or an EAN of 13 digits in Europe. Those numbers belong in the feed exactly as printed, with no spaces and no missing leading zero.
The other 135 products are the store's own label, made for it and sold nowhere else. No manufacturer ever assigned them a GTIN, so there is nothing to submit. For those, the correct answer is to mark that an identifier does not exist and to supply the brand and a manufacturer part number instead. Inventing a plausible looking number, or reusing another product's, causes a worse problem than leaving it out.
The counts here are an example. The distinction between resold and own brand is the part that decides what you submit.
Why it matters
Identifiers are how shopping platforms know that the item in your feed is the same item other retailers sell. That match is what lets your product appear on comparison surfaces, in the shopping tab and against specific product searches, so it sits right at the front of the visitors lever.
Without an identifier where one exists, listings are less likely to be shown for searches naming a specific product, and those are usually the highest intent searches available. That has a direct effect on conversion too, because a shopper searching for an exact model already knows what they want.
For a store owner the decision is a data one and it only has to be made once per product type. Reselling other brands means collecting and submitting the manufacturer's numbers properly. Making your own products means declaring that honestly and supplying brand and part number in their place.
Common mistakes
- Making up numbers to clear a warning. Invented identifiers either fail validation or match somebody else's product, and both outcomes are worse than declaring that none exists.
- Dropping the leading zero. Spreadsheets treat identifiers as numbers and quietly strip zeros, which turns a valid code into an invalid one across a whole upload.
- Marking every product as having no identifier because a few genuinely do not. Products that do have a manufacturer code are then matched to nothing and lose the searches that name them.
- Reusing one identifier across variants. Each size, colour or pack size that has its own barcode needs its own value, and sharing one collapses the variants into a single item.
Related terms and answers
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