What Is a GTIN? The Number Behind Every Barcode
A GTIN is the number printed under a product's barcode, and it is how the supply chain tells one product from another. If you already sell something with a barcode on it, you already have GTINs and you do not need new ones. If you don't, they come from GS1, the organization that issues them, and the same number is what goes into a GS1 Digital Link QR code later.
Pick up any product in your house and look at the barcode. Underneath those black lines, there's a number. That number is a GTIN (Global Trade Item Number), and it's how the entire global supply chain identifies your product.
If you're preparing for the Sunrise 2027 transition, your GTIN is the starting point. It's the number that goes into your new QR code.
GTINs in plain English
A GTIN is a unique number assigned to a product so that anyone in the world can identify it. Think of it like a Social Security number, but for products. No two products share the same GTIN.
When a cashier scans your product at checkout, the scanner reads the barcode, extracts the GTIN, and looks it up in the store's database to find the price and product name. That's it. The barcode is just a way to carry the number.
The different GTIN formats
GTINs come in four lengths. The format depends on where and how the product is sold:
| Format | Digits | Common name | Where you'll see it |
|---|---|---|---|
| GTIN-8 | 8 | EAN-8 | Very small products (a pack of gum, a lip balm) |
| GTIN-12 | 12 | UPC-A | Most products sold in North America |
| GTIN-13 | 13 | EAN-13 | Most products sold outside North America |
| GTIN-14 | 14 | ITF-14 | Cases and cartons (outer packaging for shipping) |
They're all GTINs. The number just has different lengths depending on the use case. In practice, any shorter GTIN can be converted to a 14-digit format by adding leading zeros. For example, a 12-digit UPC 012345678905 becomes the 14-digit GTIN 00012345678905. (Convert one here - note that padding never changes the check digit.)
Check a GTIN
Paste the number under any barcode. This tells you whether it is valid, which format it is, and which digit is wrong when one is.
Enter a GTIN-8, GTIN-12, GTIN-13, or GTIN-14 to validate.
The GS1 check digit uses a weighted sum algorithm (alternating x1 and x3 from right to left) to detect transcription errors. A single wrong digit will always be caught.
Do you already have one?
Almost certainly, if you sell anything that carries a barcode. The number printed under the bars is your GTIN, there is one per product variant, and you do not buy new ones to put them in a QR code. Read it off the package, or paste it into the validator above to confirm it.
If you don't have barcodes yet, GTINs come from GS1 and only from GS1. GS1 US licenses a single GTIN for $30 with no annual renewal, or a GS1 Company Prefix from $250 with a $50 annual renewal that covers ten numbers you assign yourself. Which one you want depends on how many separate products you sell, and our guide to getting a UPC code walks through the count.
Either way the number you end up with is the one that goes into a GS1 Digital Link QR code. Nothing below this point changes that; it is the detail behind it.
What's inside a GTIN?
A GTIN has three parts:
-
GS1 Company Prefix - A number assigned to your company by GS1. This is the first 6 to 12 digits (the length varies depending on how many product numbers you need). You can trace any prefix back to the GS1 Member Organisation that issued it.
-
Item Reference - A number you assign to each specific product. Combined with your company prefix, this makes the GTIN unique.
-
Check Digit - The last digit. It's calculated from the other digits using a formula, and it exists so scanners can verify they read the number correctly. If even one digit is wrong, the check digit won't match and the scanner will reject it. (Calculate one here, or check a finished number.)
For example, in the UPC 012345678905:
| Part | Digits | Meaning |
|---|---|---|
| GS1 Company Prefix | 0123456 | Identifies the company |
| Item Reference | 7890 | Identifies the specific product |
| Check Digit | 5 | Error detection |
Where GTINs come from
You can't just make up a GTIN. They're managed by GS1, the global standards organization that also maintains barcode standards. To get GTINs for your products:
- Register with your local GS1 office (in the US, that's GS1 US)
- Receive a GS1 Company Prefix
- Assign item reference numbers to each of your products
- Calculate the check digit for each GTIN
We cover this process in detail in our guide to getting a GS1 Company Prefix.
One product, one GTIN
Every distinct product needs its own GTIN. "Distinct" means any variation a customer or retailer would consider a different product:
- Different sizes (12oz vs 16oz)
- Different flavors or scents
- Different colors
- Different pack counts (single vs 6-pack)
- Different formulations
The same product in the same packaging keeps the same GTIN, even if the recipe changes slightly or you update the label design. The rule is: if a retailer or consumer would consider it a different product on the shelf, it needs a different GTIN.
GTINs and the new QR codes
With Sunrise 2027, your GTIN doesn't change. What changes is how it's carried on your packaging. Instead of encoding the GTIN in a traditional barcode (those parallel lines), you'll encode it in a GS1 Digital Link QR code that contains a URL:
https://id.sunriseqr.com/01/00012345678905
The /01/ part tells systems "what follows is a GTIN," and the 14-digit number is your GTIN (zero-padded to 14 digits). The GTIN is the same number you've always used. The carrier is what's changing.
This is why your GTIN is the starting point for the transition. If you already have GTINs assigned to your products, you're further along than you might think.