Barcode: EAN, GTIN and GS1

In short: The barcode on products contains the article number (GTIN, formerly EAN). It identifies a product uniquely worldwide.

In more detail: The most common form is the EAN-13 with 13 digits. The first digits denote the company that issued the code (not the product’s country of origin), the last is a check digit. The numbers are issued by the organisation GS1.

Our context: The product scanner checks the check digit, converts UPC-A into EAN-13 and reads barcodes by camera or photo.

In Depth

• Check digit: Weight from the right alternately with 3 and 1, sum up and round up to the next ten. Example 400840040222 → check digit 2.
• Formats: EAN-13 (Europe), UPC-A (USA, 12 digits, equals EAN with a leading 0), EAN-8 (small packs), GTIN-14 (outer cartons).
• Books: ISBN-13 starts with 978 or 979.
• GS1 prefix: 400–440 stands for Germany, 300–379 for France, 900–919 for Austria. The manufacturer may still produce the goods elsewhere.
• 2D codes: QR code and DataMatrix can hold more data, such as batch number and expiry date.

See also: Open Food Facts, Barcode scanner