Electronic commerce over the Internet is growing at an increasing pace worldwide. Maintenance of electronic commerce systems is thus becoming an increasingly important IT activity. In this paper the legal issues concerned with the maintenance of electronic commerce systems are examined based on detailed case studies in two U.K.-based organizations, a marketing organization and a retail organization. Even seemingly trivial maintenance activities of electronic commerce systems such as changing Web site text can have legal implications due to the variety of advertising, consumer protection, data protection and other legislation and regulation that potentially applies to electronic commerce activities. In addition, the potentially global nature of electronic commerce activities implies that maintenance activities of electronic commerce systems need to comply not only with the legislation and regulation within the country of the seller, but also potentially with the legislation and regulation within the country of the consumer as well.