Incorporated in 1979 as MasterCard International, Inc. (presently recognised as Mastercard) is an American multinational financial services corporation with its headquarters at the Mastercard International Global Headquarters in Purchase, New York. It was formerly known as MasterCard International, Inc. (now known as MasterCard since 2016). The Global Operations Headquarters is situated in O'Fallon, Missouri, which is a town in the county of St. Charles, Missouri. The city was founded in 1836. Its primary activity is the processing of payments between the banks of merchants and the card-issuing banks or credit unions of buyers who make transactions using debit, credit, or prepaid cards bearing the "Mastercard" name. This is done on a global scale. Because of its public stock market listing in 2006, Mastercard Worldwide has become a household name. In the years leading up to its first tender offer, Mastercard Worldwide was a cooperative owned by more than 25,000 financial institutions who issued the company's branded debit cards.
In reaction to the BankAmericard, which was issued by Bank of America and eventually became the Visa credit card issued by Visa Inc., an alliance of regional bankcard associations formed the Mastercard, which was initially known as Interbank from 1966 to 1969 and Master Charge from 1969 to 1979.