GuideUpdated October 28, 2026
SKU vs UPC vs EAN: which code goes on your labels
A SKU is a code you invent to track stock. UPC and EAN are standard product numbers that identify the same product anywhere. Any of them can be printed as a barcode, but they do different jobs.
At a glance
| SKU | UPC-A | EAN-13 | |
|---|---|---|---|
| What it is | Your own stock code | Global product number | Global product number |
| Length | Any | 12 digits | 13 digits |
| Characters | Letters, numbers, dashes | Numbers only | Numbers only |
| Who assigns it | You | Issued under a GS1 company prefix | Issued under a GS1 company prefix |
| Mostly used in | Your own store and stockroom | US and Canada | Most other countries |
| Shopify field | SKU | Barcode (ISBN, UPC, GTIN, etc.) | Barcode (ISBN, UPC, GTIN, etc.) |
| Printed as | Code 128 | UPC-A | EAN-13 |
SKU
A stock keeping unit is a code you choose, like TEE-NVY-M for a navy medium tee. It means something to you and no one else, so two shops can use the same SKU for different things. Shopify stores it in each variant's SKU field.
SKUs work well as barcodes inside your own business: receiving stock, counting, picking orders and selling at your own counter. Print them as Code 128, a barcode type that handles letters, numbers and dashes.
UPC and EAN
UPC-A and EAN-13 are GTINs, global trade item numbers. Each one identifies one product, worldwide, and is issued under a company prefix licensed from GS1. The last digit is a check digit calculated from the others, so a mistyped number is caught.
Retailers and marketplaces that list the same product from many sellers often require a GTIN. If you buy products from a brand, the UPC or EAN is usually already printed on the packaging, and you can enter it in Shopify's Barcode field.
Which should go on your labels?
- The product already has a UPC or EAN: print that. It matches the packaging and any supplier records.
- You make the product and only sell it yourself: print the SKU as Code 128. No purchase needed.
- You plan to sell through a retailer or marketplace that asks for GTINs: get codes from GS1 for your country, enter them in Shopify, and print those.
To fill the fields for many products at once, see how to add barcodes to Shopify products.
In Crisp Labels, set Barcode shows to the Barcode field or SKU. With Barcode type on Automatic, valid 12- and 13-digit codes print as UPC-A or EAN-13, and everything else prints as Code 128.
Shopify's help center says that in Shopify POS you can find a product by scanning or searching any of its barcodes, or its SKU (source).
Common questions
- Is a SKU the same as a barcode?
- No. A SKU is a code you make up to track your own stock. A barcode is a way of printing a value so a scanner can read it. You can print a SKU as a barcode (usually Code 128), and you can print a UPC or EAN as a barcode.
- Do I need to buy UPC codes?
- Only if a retailer or marketplace you sell through requires GS1 product codes. For labels used in your own shop and stockroom, printing your SKUs as Code 128 barcodes works without buying anything.
- What's the difference between UPC and EAN?
- A UPC-A has 12 digits and is used mostly in the US and Canada. An EAN-13 has 13 digits and is used in most other countries. A UPC-A can be written as an EAN-13 by adding a leading zero, and scanners read both.
- Can Shopify POS scan SKU barcodes?
- Shopify's help center says that in Shopify POS you can find a product by scanning or searching any of its barcodes, or its SKU. Test one label at your own checkout before printing a batch.