Mastercard Incorporated is an American multinational financial services corporation headquartered in the Mastercard International Global Headquarters in Purchase, New York. The Global Operations Headquarters is located in O'Fallon, Missouri, a municipality of St. Charles County, Missouri. Throughout the world, its principal business is to process payments between the banks of merchants and the card-issuing banks or credit unions of the purchasers who use the Mastercard brand debit, credit and prepaid cards to make purchases. Mastercard Worldwide has been a publicly traded company since 2006.