This paper offers an adoption study of Mobile Information Systems (MobIS) in the banking services for the general public in the Spanish market. The approach is done through the study of the interaction between these MobIS and banking organizations. An evaluation model of adoption of MobIS was applied in order to establish classifications of Spanish banks in function of their level of adoption of banking mobile services. Considering this study as a reference, a wider outlook of all the different mobile services offered by Spanish banks is shown and finally, as a case of study, a concrete application to the m-broker services is made. The different levels of adoption can be considered as different stages of a hypothetical adoption model. The main factors that determine further stages will be studied, and how these factors imply greater levels of interaction between the organization (its different dimensions), its strategic level and the MobIS.