For years, Visa and Mastercard rules have said that if a merchant doesn’t add a surcharge for all credit card transactions, including those made with another card company such as American Express, then they couldn’t impose a surcharge on Visa and Mastercard cards either. American Express rules, in turn, disallowed surcharging unless the merchant imposed that charge for all other payments, including debit cards, but Visa and Mastercard forbid surcharging for debit cards, the affidavit explained.
