Methods and systems for dynamically determining interchange fees. In an embodiment, an acquirer computer transmits a payment card account authorization request to a payment processing network, and receives an authorization response authorizing the transaction and comprising a spending history indication reflecting a compilation of spending history data of a group of payment card accounts that qualify for dynamic interchange rate setting. The acquirer computer then stores the spending history indication, transmits the authorization response to a merchant processing system computer, receives a clearing file from the merchant processing system computer, determines that an interchange rate depends on the spending history indication, selects an interchange rate from an interchange rate selection database based on the spending history indication, calculates an interchange fee based on the interchange rate, and transmits the clearing file and the interchange fee to the payment network for clearing of the transaction.