Usually for sales/services transactions it is a fee that a merchant's bank (the acquiring bank) pays a customer's bank (the issuing bank); and for cash transactions the interchange fee is paid from the issuer to acquirer, often called reverse interchange. In a credit card or debit card transaction, the card-issuing bank in a payment transaction deducts the interchange fee from the amount it pays the acquiring bank that handles a credit or debit card transaction for a merchant.