How to Generate Barcodes for Products

Generating Product Barcodes

Every product sold at retail needs a barcode. The process involves obtaining a company prefix, assigning product numbers, generating the barcode image, and ensuring print quality meets scanner requirements.

Getting a Company Prefix

In the US, company prefixes are issued by GS1 US. The prefix length determines how many unique products you can number — a 7-digit prefix allows 100,000 products, while a 10-digit prefix allows 100. Costs range from $250 for small businesses to $10,500 for enterprises, plus annual renewal fees. Third-party barcode resellers offer individual UPCs, but major retailers may reject them.

UPC vs EAN

UPC-A (12 digits) is the North American standard. EAN-13 (13 digits) is used internationally. A UPC-A can be converted to EAN-13 by prepending a zero. If you sell internationally, register for EAN-13 through your national GS1 organization. The last digit is always a check digit calculated from the preceding digits.

Barcode Image Generation

Generate barcode images at the exact print dimensions — scaling introduces errors. The minimum bar width is 0.264mm (1X magnification) for UPC/EAN. Most retail barcodes print at 80-200% magnification. Include human-readable digits below the bars. Use vector format (EPS) for print production to avoid rasterization artifacts.

Print Quality Verification

Use a barcode verifier (not just a scanner) to grade your printed barcodes. Verifiers check symbol contrast, modulation, decodability, and quiet zones, assigning a grade from A to F. Most retailers require grade C or better. Common causes of low grades include ink spread (dot gain), insufficient contrast, and truncated bars.