A method includes receiving an authorization request for a purchase transaction, and determining whether the authorization request arose from proximity-reading a proximity payment device. The method further includes mapping a first account number included in the authorization request into a second account number associated with the first account number if it is determined that the authorization request arose from proximity-reading a proximity payment device and if the first account number is qualified for mapping. In addition, the method includes transmitting the authorization request to an issuer financial institution with the second account number substituted for the first account number in the authorization request.