# GS1 company prefix

> A GS1 company prefix is the block of barcode numbers a business rents from GS1 so its products can be identified worldwide.

- Source: https://storestandards.com/glossary/gs1-company-prefix/
- Updated: 2026-08-14
- Author: Priya Raghunathan, Founder, engineer, Store Standards

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GS1 is the body that hands out these blocks. It is a membership, renewed
yearly, not a one-off purchase.

## How the number is built

Your prefix is the front of every [GTIN](https://storestandards.com/glossary/gtin/) you own. You add
your own item numbers after it, and the
[check digit](https://storestandards.com/glossary/check-digit/) goes on the end.

A short prefix gives you more item numbers and costs more. A small maker with
twenty products does not need the block a supermarket brand needs.

## Do you actually need one

Only if you are the brand. If you buy stock from suppliers and resell it, the
barcodes are already on the boxes and they belong to whoever made the goods.
Use those.

You need your own prefix when you make the product, when you sell it under
your own label, or when a retailer or marketplace asks for a barcode you can
prove is yours.

## Where it goes wrong

Cheap barcodes bought from a reseller. They are real numbers, issued years
ago to a company that has since sold them on. They scan, and then a
marketplace checks the GS1 registry and finds somebody else's name against
them.

For anything that never leaves your own stockroom, skip all of this. Print
[Code 128](https://storestandards.com/glossary/code-128/) labels and spend the membership fee on
something else.

## Related terms

- [GTIN](https://storestandards.com/glossary/gtin/): A GTIN is the number that identifies a product worldwide. The barcode on the box is just a way of printing it.
- [EAN](https://storestandards.com/glossary/ean/): An EAN is the thirteen-digit retail barcode used across Europe and most of the world outside North America.
- [Code 128](https://storestandards.com/glossary/code-128/): Code 128 is a barcode you generate and print yourself. It holds letters as well as numbers, and it is any length you want.