Card Networks / Card Brands

Card networks, also called card brands or payment networks, are the companies that own and operate the infrastructure connecting Issuers, Acquirers, and merchants in a card payment transaction. The major global networks are Visa, Mastercard, American Express, Discover, and JCB. UnionPay is the dominant network in China.

Card networks perform several distinct functions. They maintain the technology infrastructure (the "rails") over which authorization, clearing, and settlement messages travel. They set the rules governing how participants must behave, covering everything from fraud liability to data security to acceptable merchant categories. They establish Interchange Fees and Scheme Fees. And they own the brand promise to consumers that their card will be accepted at participating merchants worldwide.

American Express and Discover operate on a "closed-loop" model: they act as both network and issuer, issuing cards directly to consumers and maintaining a direct relationship with both sides of the transaction. Visa and Mastercard operate on an "open-loop" model: they own the network but partner with banks (issuers) to issue cards and with acquiring banks to accept them.

Networks also set the compliance standards that all participants must follow. PCI DSS itself was created by the major card brands through the PCI SSC (PCI Security Standards Council) to standardize data security requirements across the industry. Compliance with card network rules is not optional, non-compliant participants face fines, restrictions, and ultimately the loss of network access.