A card association is a network of issuing banks and acquiring banks that process payment cards of a specific brand.
Familiar payment card association brands include Visa, MasterCard, American Express, Discover, Diner's Club, and JCB. Visa, MasterCard and American Express issuers co-brand with their card association. for example, "WellsFargo-Visa" and "Citi-MasterCard".
Card associations Visa and MasterCard each comprise over 20,000 card issuing banks.
Among United States consumers alone, over 600,000,000 payment cards are in circulation.
Worldwide, Visa issuers have over 1.5 billion payment cards in circulation .