# 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.

- Source: https://storestandards.com/glossary/code-128/
- Updated: 2026-08-14
- Author: Tom Beckwith, Engineer, Store Standards

---

That freedom is the point. An [EAN](https://storestandards.com/glossary/ean/) can only hold thirteen
digits, and only ones GS1 gave you.

## What to use it for

- Products with no barcode from the supplier
- Your own [SKU](https://storestandards.com/glossary/sku/), printed on a shelf label
- [Bin location](https://storestandards.com/glossary/bin-location/) labels on the racking
- Anything internal that a scanner needs to read

Every handheld scanner made in the last twenty years reads Code 128 with no
setup. So does a phone camera.

## Keep it short

Code 128 gets physically wider as you add characters. A twenty-character code
on a small label prints so narrow that a cheap scanner cannot resolve the
bars.

Twelve characters or fewer is a good ceiling for a shelf label. If your codes
are longer than that, the code is the problem, not the printer.

## Where it goes wrong

A printed internal code ends up in the barcode field instead of the real one
off the box. It scans in your stockroom and it fails everywhere else, because
no marketplace has ever heard of `ACM-HOOD-BLU-M`.

Keep the two apart. The supplier's number goes in the barcode field. Yours
goes in the SKU field, and Code 128 is how you make yours scannable.
[Which barcode goes where](https://storestandards.com/blog/barcode-types-for-shopify-stores/) has the
full set.

## Related terms

- [SKU](https://storestandards.com/glossary/sku/): A SKU is your own code for one exact thing you sell, down to the size and colour. You invent it, and only your shop uses 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.
- [Bin location](https://storestandards.com/glossary/bin-location/): A bin location is the address of a place in your stockroom, so anyone can be told where to find a product without being shown.