UPC vs EAN vs GTIN: which barcode does your Shopify store need?
GTIN is the family name. UPC and EAN are the two common members. Which one you need depends on where you sell.
The short version
| Format | Digits | Used for |
|---|---|---|
| UPC-A | 12 | Retail products, mainly in the US and Canada |
| EAN-13 | 13 | Retail products almost everywhere else |
| EAN-8 | 8 | Very small packs where EAN-13 does not fit |
| ITF-14 | 14 | Outer cartons and cases (GTIN-14) |
| Code 128 | Any | Internal use: SKUs, shelves, your own codes |
What GTIN means
GTIN (Global Trade Item Number) is the name for all product numbers issued under the GS1 system. A UPC-A is a 12-digit GTIN, an EAN-13 is a 13-digit GTIN. Marketplaces and Google often ask for a "GTIN", which means one of these.
UPC and EAN are the same number system
A 12-digit UPC-A becomes a valid EAN-13 by adding a leading zero, and scanners read both. SGT prints a 12-digit UPC-A correctly even when the label format is set to EAN-13, so the label scans as exactly the number in Shopify.
When you need GS1 codes
Buy a company prefix from your local GS1 office if you sell through retailers or marketplaces that require registered GTINs. The prefix identifies your business, and every code you build from it is yours. SGT builds valid codes from that prefix, with correct check digits, and skips numbers already used in your store.
When internal codes are enough
If the barcode is only for your own shop, stockroom and Shopify POS, you do not need GS1. Use internal codes, or simply print your SKU as a Code 128 barcode. They scan perfectly in your own systems.
The check digit
The last digit of every UPC, EAN and ITF-14 code is calculated from the others. If it is wrong, scanners reject the code or the label tool silently changes it. SGT refuses to print a code whose check digit does not fit its format, rather than print one that scans as a different number.
Prefer video? Watch the 90-second SGT tour on YouTube.
Common questions
Can I make up my own UPC numbers?
You can generate numbers in the right format, but they are only legitimately yours if the prefix is licensed to you by GS1. For internal use, Code 128 or internal codes avoid any conflict.
Is a GTIN the same as a SKU?
No. A SKU is your own internal code. A GTIN is a standardised number registered through GS1. Many stores use both.