EANUPCCodes

EANUPCCodes, more commonly referred to as EAN/UPC codes, are standardized numeric identifiers used to uniquely identify trade items in retail and logistics worldwide. They are part of the GS1 system and are designed to enable fast, accurate scanning and data linkage across supply chains. In practice, they represent Global Trade Item Numbers (GTINs), of which the most common formats are EAN-13 (13 digits) and UPC-A (12 digits). The EAN family also includes shorter forms such as EAN-8, used for very small items, but the term EAN/UPC typically refers to the 12- and 13-digit forms.

EAN-13 and UPC-A numbers share the same underlying structure and check-digit algorithm. The numeric string encodes the item and its attributes; the final digit is a check digit used to verify data integrity. For UPC-A, the check digit is calculated from the first 11 digits by summing digits in odd positions, multiplying by 3 the sum, adding the even-positioned digits, and computing the digit that brings the total to a multiple of 10. EAN-13 uses a similar modulo-10 check, but applies a weight pattern of 1 and 3 to the first 12 digits before computing the final check digit. The first digits also determine the country or GS1 member region, and the leading digit in EAN-13 can imply a country code.

GS1 member organizations allocate GTINs to brands and products, and retailers integrate them into electronic catalogs, inventory systems, and point-of-sale terminals. Barcodes encode the GTIN so scanners can retrieve product data from centralized databases. The 13-digit EAN version can be displayed as a UPC-A by padding a leading zero, facilitating compatibility between regional systems.

Although the codes themselves are simple numbers, their issuance and rules are governed globally by GS1. Standards cover not only barcode symbology but data carrier formats, encoding in logistics barcodes (like GS1-128), and data synchronization across trading partners. EAN/UPC codes are widely adopted in supermarkets, online marketplaces, and logistics networks, forming a core layer of product identification worldwide.