The present invention relates to a method and system for processing transactions involving accounts for reimbursing medical expenses or patient responsible balances, wherein the accounts may be handled by multiple payors having multiple transaction substantiation requirements. Examples of such accounts include flexible spending accounts, health reimbursement arrangement accounts, medical savings account, health savings account and the like. The system and method of the present invention allow an employer that uses multiple payors for administering the aforementioned accounts to distinguish its employees-based on their associated payors in order to determine the proper transaction substantiation requirement per each employee and associated payor without having required to collect payor data at the employee level.