Mastercard  Mastercard Incorporated (stylized as MasterCard from 1979 to 2016 and mastercard since 2016) is an American multinational financial services corporation headquartered in the Mastercard International Global Headquarters in Purchase, New York, United States. The Global Operations Headquarters is located in O'Fallon, Missouri, United States, 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. 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. Mastercard, originally known as "Interbank" from 1966 to 1969 and "Master Charge" from 1969 to 1979, was created by an alliance of several regional bankcard associations in response to the BankAmericard issued by Bank of America, which later became the Visa credit card issued by Visa Inc. Although BankAmericard's debut in 1958 had been a notorious disaster, it began to turn a profit by May 1961. Bank of America deliberately kept this information secret and allowed then-widespread negative impressions to linger in order to ward off competition. This strategy was successful until 1966, when BankAmericard's profitability had become far too big to hide. From 1960 to 1966, there were only 10 new credit cards introduced in the United States, but from 1966 to 1968, approximately 440 credit cards were introduced by banks large and small throughout the country. These newcomers promptly banded together into regional bankcard associations. One reason for why most banks chose to join forces was that at the time, 15 states prohibited branch banking and required unit banking. A unit bank is one which can legally operate only at a single site and is thereby forced to remain small. By joining a regional bankcard association, a unit bank could quickly add a credit card to its lineup of financial products, and achieve economies of scale by outsourcing tedious back office tasks like card servicing to the association. Such associations also enabled unit banks to aggregate their customer bases and merchant networks in order to make a credit card useful for both customers and merchants; early credit cards had failed because they could only be used within a small radius around the issuing bank. In 1966, several regional bankcard associations joined together to form the Interbank Card Association (ICA). The Interbank branding in 1966 initially consisted only of a small unobtrusive lowercase "i" inside a circle in the lower right-hand corner of the front of each Interbank card; the rest of the card design was the prerogative of each issuing bank.