Mobile phones and other small and powerful portable devices have revolutionized personal communication and affected the lifestyles of the people in the industrialized world. Following credible estimates, in a few years there will be one billion of such portable devices. An emerging trend is the electronic commerce performed using mobile terminals, often called mobile commerce. Mobile commerce environments are characterized by high complexity, including myriads of technical and organizational aspects. This property makes it difficult to distinguish the more fundamental issues, structures, and concepts in mobile commerce from the hype. To capture the fundamental aspects of mobile commerce environments, we have developed a model. It covers fundamental static aspects of the m-commerce environment and their relationships. We distinguish four spheres of concern: Regulatory Frameworks, Business Models, Enabling Technologies, and the Global Infrastructure. Rather than providing technical details of m-commerce environments, our aim is to model invariant properties that will evidently persist for years to come. Making use of the abstraction capabilities provided by the object-oriented approach, the model is represented by OO structure diagrams.