Visa Inc., headquartered in San Francisco, is a global payment card services giant that facilitates electronic funds transfers worldwide through its branded credit, debit, and prepaid cards—though it doesn't issue cards itself, instead providing these products to financial institutions. Its massive network, VisaNet, processed an astonishing 257.5 billion transactions worth $14.2 trillion in 2025, operating from four heavily secured data centers in the U.S., England, and Singapore that can handle up to 30,000 simultaneous transactions. The company traces its roots to September 18, 1958, when Bank of America launched the BankAmericard program in Fresno, California, after a pioneering mass mailing of 65,000 unsolicited credit cards—a concept driven by Joseph P. Williams. After licensing the program to other banks in 1966, Dee Hock helped transform it into an independent organization, National BankAmericard, in 1970, which was renamed Visa in 1976. Today, Visa is the world's second-largest card payment organization (behind China UnionPay since 2015), yet it remains the dominant force outside China, commanding a 50% market share of total card payments.