Interchange is a fee paid between banks for the acceptance of a card based transactions.Card issuers charge merchants an interchange fee every time a debit or credit card is used to make a purchase. Technically, the interchange fee is charged by the card issuer, however the merchants pay the fee to the company that processes their card transactions. As a result, some card processors are capitalizing on the change. The interchange fee rate is determined by Visa and MasterCard. Until the Durbin-law is imposed the average interchange fee charged from merchants was 44 cents per transaction. The Durbin Amendment imposes a cap on this fee. Originally set to take effect July 21, limiting banks with more than $10 billion in assets to a maximum 12 cent fee charged to merchants per debit card transaction. After the Durbin Amendment final bill takes effect on October 1, 2011, the fee is capped at 21 cents, plus 0.05% and an additional discretionary 1 cent for institutions employing effective fraud prevention initiatives.Issuers eligible for this adjustment, could then receive a maximum interchange fee of 24 cents for the average debit card transaction.