Internet E-Commerce has been flourishing for the last few years, especially with the advent of world wide web. Mobile Electronic Commerce has started recently to appear in the scene by exploiting the advantages of internet, mobile computing and mobile communications in order to provide a large number of advanced services to mobile users. The potentials of mobile e-commerce are enormous while related technical, business and legal issues become more complicated. The goal of this paper is to present and discuss problems associated with the trading and billing of tangible and intangible goods in an environment, where mobile handheld devices are used to conduct transactions and to identify requirements for these. Index Terms-- Transaction Processing, Mobile Electronic Commerce, Mobile Computing, Wireless Application Protocol, Wireless Networks I. INTRODUCTION Electronic Commerce (E-Commerce, EC) concerns the digitization of markets and the emergence of a new industry to sustain these elec..