An encrypted payment message is received from a buyer relating to a transaction with a merchant. The payment message is parsed using a first parsing algorithm to obtain merchant identifying information. The merchant identifying information is associated with at least a second parsing algorithm or at least one settlement algorithm. The payment message is parsed using the second parsing algorithm to obtain payment information for the transaction. A first settlement algorithm is applied to the payment information to determine an adjusted interchange rate. The payment information including the adjusted interchange rate is submitted to a third party settlement processor on behalf of the merchant, using a payment algorithm. A second settlement algorithm applied to the payment information determines a buyer rebate which can be submitted to the settlement processor. A transaction result is reported to at least one of the merchant or the buyer.