A method is provided for using an application (18) in a mobile station (1). The application has a first mode of operation and a second mode of operation. The first mode of operation is passive. In the second mode of operation the application (18) controls a master control unit (MCU) of the mobile station (1). Also provided is a system for making payments, comprising at least one mobile station (1) which has an associated application (18), a component for using the application (18), and a first transceiver (IR, 20) for providing local data transfer. The system also comprises at least one cash register (21) or the like, which has a second transceiver for providing data transfer (IR2). The application (18) has a capability for causing data to be transferred from the first transceiver (IR) to the second transceiver (IR2).