Although credit cards can be convenient, help build credit, and earn rewards, users also need to keep an eye out for a new surcharge. Under a 2012 settlement with Visa, MasterCard, and other major banks, merchants can pass on the costs of credit-card processing fees to consumers, charging them 1.5 percent to 4 percent of the purchase price, not including sales tax. Only 10 states -- including California, New York, and Texas -- prevent merchants from imposing the fees on consumers. However, consumers must be notified up front. "Merchants are required to put a notice at the entrance to their store and at the checkout register and print it on your receipt," says North Carolina Attorney General Roy Cooper. "They also have to notify you before you make a credit card purchase online that they are going to charge the surcharge fee."