However , in 1991 , several restaurants in Boston started accepting Visa and MasterCards , even encouraging their customers to use them . These cards had a much lower fee than American Express fees , which at the time charged 4 % for each transaction . However , in 1991 , several restaurants in Boston started accepting and encouraging the use of Visa and MasterCard because of their far lower fees as compared to American Express ' fees at the time ( which were about 4 % for each transaction versus around 1.2 % at the time for Visa and MasterCard ) .