You can log in to your MasterCard account through the website of the bank that issued the card, according to MasterCard.us. MasterCard can't access the account information of any cardholders.
Banks provide credit cards linked to a line of credit, debit cards linked to a checking account or prepaid debit cards with the MasterCard logo, explains the company. Cardholders may then use their cards at any store, restaurant or website that accepts MasterCard. The company supplies and maintains the network that allows transactions between banks and retailers. For help with lost or stolen cards, contact MasterCard at the number listed on its website.