Abstract: A method for processing a financial transaction using an interchange network computer coupled to a database is described. The transaction is initiated with a transaction card associated with a linked account. The method includes receiving, at the interchange network computer, a linked account data file for the first transaction card. The data file includes data associating the first card with a first secondary account and data linking the first secondary account to a first primary account. The method also includes storing the data file within the database and receiving a first authorization request message for the first transaction. The method also includes determining, based on data included within the first authorization request message, that the first card is associated with the first secondary account and processing the first authorization request message by applying at least one processing code associated with the first primary account to the first transaction.