How to Add Barcodes to Your Products

Get official numbers from GS1

If your products will be sold in shops or on large marketplaces, join GS1 in your country (GS1 US in the USA) and get a company prefix. From it you create your product numbers (GTINs), each ending with a check digit.

For codes that never leave your business, such as shelf labels or asset tags, you do not need GS1: use Code 128 with your own numbers, or, for in-store codes, the restricted prefixes 200 to 299 as your GS1 office allows.

Give each variant its own number

GS1's rule is simple: each product variation needs its own GTIN. A T-shirt in three sizes and two colors needs six numbers. A sequence makes this easy: enter the first number in the batch section and the tool counts up and adds each check digit:

• 012345678905
• 012345678912
• 012345678929
• … and so on, up to 500 at a time.

Choose the barcode type and size

Use UPC-A or EAN-13 for products sold in shops, ITF-14 for cartons, and Code 128 for shipping labels and internal codes.

Print EAN-13 and UPC-A at 100% (0.330 mm bars) when you have the space. You can go down to 80% (0.264 mm) on small packs and up to 200% (0.660 mm). Avoid cutting the bars shorter than the standard height, because short barcodes are harder to scan.

Place it where it scans

Keep the clear margins on both sides free of text and graphics. Use black or another dark color for the bars on a white or light background, never red bars and never light bars on a dark background.

On transparent packaging, print a white background behind the bars instead of relying on the contents to provide one.

Test before you print a full run

Mistakes on packaging are expensive. Before printing, check every number with the validator, print one label at the real size, and scan it with a phone barcode app or the scanner you will use. Barcode verifiers grade print quality professionally, and some GS1 offices, such as GS1 Germany, offer this as a service.

Look ahead: 2D barcodes

GS1's Sunrise 2027 initiative is moving retail towards scanners that also read 2D barcodes, such as QR codes that carry the same GTIN as your UPC or EAN. Brands are asked to add 2D codes to existing packaging, so keep your UPC or EAN for now. You can make a QR code with our QR code generator.

Checklist

Before you send artwork to the printer:

• Every number comes from your own GS1 company prefix, and every variant has its own number.
• Every check digit is valid.
• The bars are at least 80% of standard size and not cut short.
• Dark bars on a light background, with clear margins on both sides.
• One sample label printed at real size and scanned successfully.