Processing fees are broken up into two portions: The interchange fee and the processor’s margin. Interchange Rates for card brands like Visa and Mastercard are determined by the card brands and issuing banks. All credit card processors adhere to the exact same interchange rates. To arrive at this base cost for each transaction, they take into consideration factors such as: Type of payment card, card brand, the type of business accepting the card, the transaction type, the cost of processing this transaction, risk factors such as fraud, consumer rewards and perks, the second portion of your processing costs - the processor margin - is made up by your payment processor. How much you pay to accept payments will depend on which pricing model your processor uses and how much they make from their margin.