A method and system for processing a transaction based on biometric data and access data is disclosed. Different accounts and providers may be used to process transactions, using different message formats, based on user-configured mappings. In one example, the method includes receiving, by a message processing system, an authorization request message from an access device, the authorization request message comprising a biometric template and access data. An interaction entity record identifier, associated with an interaction entity from among a plurality of different interaction entities that process messages in different message formats, may be retrieved. The authorization request message may be converted from a first format to a second format, the second format being compatible with message processing by the interaction entity. The converted authorization request message may be transmitted to the interaction entity for determining whether to authorize the transaction.