Who defines interchange?
Interchange is defined by the card associations: Visa, MasterCard, and Discover. Interchange is the "base rate" that all merchants pay for any given credit/debit card.
One of the biggest jobs that Visa/MasterCard/Discover have is to set/define the interchange rates. As a reminder - interchange is the cost paid back to the cardholder's issuing bank for every transaction a merchant accepts. It's a rate that all merchants pay, and all issuing banks get the same interchange fees. Essentially, interchange is a "buy rate" for credit card sales.
Every year, the card associations update their interchange rates. Usually, the rate changes are very modest - the rates stay roughly untouched year over year, minus a few updates here and there. You can see the tables here (they're complicated!)
Remember - Visa/MasterCard/Discover don't keep the interchange rates. That money goes back to the customer's bank, to cover the costs of issuance and risk mitigation. The card associations do make money, but it's much less. You can see their cut here.
We're serious about saving money.
AND is dedicated to getting your processing rates as close to zero as possible. We utilize membership pricing along with cash discounting and surcharging programs to maximize savings. Let our analysts review your statements and see how much money we can put back in your pockets.