MasterCard is a global bank card payment transaction processor, whose portfolio of brands and products include Maestro, Cirrus and MasterCard PayPass. It partners with financial institutions that issue credit cards, and with merchants who accept those cards. MasterCard offers a network of more than 28 million acceptance locations around the world and, in many cases, guarantees payment through its system. Through its merchant agreements, it sets payment and charge-back policies that affect consumers. It does not, however, issue cards, set annual fees, determine annual percentage rates on cards or solicit merchants to accept cards.