Abstract: A computer-implemented method of exchanging data is provided. Before a transaction, the transaction including exchange of data: associating a plurality of funding sources with an account; defining one or more rules, each corresponding to a condition and a specified funding source from the plurality; assigning a priority to each rule; and storing rules and priorities associated with the account. At a time of a transaction: receiving data describing the transaction; determining if the transaction satisfies any condition of the rules, the funding source from the satisfied rule being the determined funding source unless more than one rule has a satisfied condition. In the event of more than one rule with a satisfied condition, the highest priority rule among all satisfied conditions determines the funding source to be charged. In the event of determining that no condition is satisfied, charging any one of the plurality of associated funding sources.