Mastercard Inc. is an American multinational payment card services corporation headquartered in Purchase, New York. It provides payment transaction processing and other related-payment services, including travel-related payments and bookings. Its principal business globally is to process payments between the banks of merchants and the card-issuing banks or credit unions of purchasers who use its branded debit, credit and prepaid cards to make purchases. Mastercard has been publicly traded since 2006. Mastercard was created by an alliance of several banks and regional bankcard associations in response to the BankAmericard issued by Bank of America, which later became Visa and remains its biggest competitor. Both companies have faced numerous antitrust lawsuits. Prior to its initial public offering, Mastercard Worldwide was a cooperative owned by the more than 25,000 financial institutions that issue its branded cards.