Abstract: Managers and their decisions can be successful only if they research with correct and relevant information. Because it is not possible to implement an experiment with institutions that are to be managed, it is necessary to provide artificial experiments within an appropriate model. This is the way how simulation models are introduced into managerial research. The aim of this paper is to introduce a simulation model and its implementation in MATLAB that can be used for estimation of total monthly cost for a selected mobile phone tariff. Finally the properties for different parameters and other tariff are discussed as well.