EAN-13 and UPC-A are not competing technologies. Both are defined by the same standard, ISO/IEC 15420, and any scanner made this century reads both. A UPC-A is, structurally, an EAN-13 whose first digit is zero.
The real question is administrative, not technical: which number you've been issued, and which format the retailers you sell through expect on the label.
Same standard, one digit apart
UPC-A encodes 12 digits (a GTIN-12); EAN-13 encodes 13 (a GTIN-13). Pad a GTIN-12 with a leading zero and you have its GTIN-13 — the same product, the same bars, two written forms.
This is why databases, marketplaces, and POS systems treat 012345678905 and 0012345678905 as the same item. The check digit calculation is the same modulo-10 algorithm across both.
Where each format is expected
UPC-A is the convention on products sold in the United States and Canada. EAN-13 is the convention everywhere else. Since the GS1 'Sunrise' deadline of 2005, North American retail systems have been required to accept 13-digit codes too, so the distinction is now cosmetic in most stores.
Practical rule: if your GS1 prefix was issued by GS1 US and you sell mainly in North America, print UPC-A. If your prefix comes from any other GS1 member organization, print EAN-13. If you sell on both sides of the Atlantic, one EAN-13 on the package serves everywhere.
What Amazon and marketplaces actually check
Amazon, and most large marketplaces, validate the GTIN you enter against the GS1 database — they check that the prefix is registered and, increasingly, that it's registered to your brand. A made-up number, or a 'recycled' UPC bought cheap from a reseller of pre-1990s prefixes, risks listing removal.
If you sell at retail or on marketplaces, get your number from GS1 directly: either a company prefix (your own block of numbers) or a single GTIN for a one-product business. For internal inventory, samples, and barcodes that never cross a till, any digits work and GS1 is not involved.
Printing either one correctly
Nominal size is 37.29 × 25.93 mm at 100% magnification, with an allowed range of 80% to 200% per the GS1 General Specifications. Below 80%, scan failures at the till rise sharply.
Keep the quiet zones (the light margins flanking the bars), print dark bars on a light background, and never print bars in red — retail laser scanners read red as white.
Frequently asked questions
- Can I sell a product with a UPC-A barcode in Europe?
- Yes. European scanners read UPC-A and treat it as the equivalent EAN-13 with a leading zero. The reverse also works in North America at any modern register.
- Can I turn my UPC into an EAN by adding a zero?
- The 13-digit form with a leading zero already is your product's GTIN-13 — no new number needed. Enter the 12-digit form where a system asks for a UPC and the zero-padded form where it asks for an EAN; they identify the same product.
- Do I need a separate barcode for every product variant?
- Yes. Every variant a shopper could choose between — each size, color, flavor, and pack count — needs its own GTIN, because the till and the inventory system can only tell products apart by that number.
Related tools
- EAN-13 barcode generator — 13-digit retail barcode with automatic check digit.
- UPC-A barcode generator — 12-digit North American retail barcode.
- Barcode generator — All 30+ supported symbologies in one tool.