Interchange rates are generally made up of a percentage of the amount processed plus a transaction fee. E.g. 1.50% plus $.10. On a $100 purchase the interchange cost would be $1.60.
Interchange is also effected by the method and timing of the card processing. For example, a card that is read through a terminal will have a lower interchange rate than a card that is key entered.
There are several hundred interchange rates across Visa, MasterCard, American Express and Discover. However, in most cases a merchant will see around 10 different rates on their statements but it can vary depending on the type of merchant.
Interchange pass-thru pricing will show-up on a statement with each of the interchange categories that were processed within the month. While it may be confusing it is generally the best method to keep the overall cost to a minimum. We recommend that when trying to compare rates, calculate the Effective Rate, which is the total amount of fees charged divided by the total dollar amount processed.