Abstract: An electronic commerce system supports on-line stores that are accessible by a set of buyers. Each buyer is associated with one of a set of one or more organizations. The electronic commerce system includes the ability to define a base trading agreement with terms and conditions for associated buyers and on-line stores, store settings with terms and conditions associated with one of the on-line stores, and customer preferences trading agreements, associated with organizations. The system includes an application interface for returning a set of governing terms and conditions for a buyer-store electronic commerce session, based on the associated base, store settings and customer preferences trading agreements.