An interchange rate is the fee that you—as a merchant—must pay with every credit card (or debit card) transaction. These rates are set by the financial institution or issuer of the card. Fees can vary depending on the type of card, and the type of transaction; standard cards such as a basic Visa card will have a lower interchange fee than a speciality card. Similarly, smaller, everyday transactions like groceries will have lower fees than those associated with high-end purchases like airline travel.