A changeable cover for an electronic device and method of using same in a payment system is provided. The cover has a transponder responsive to interrogation by an electric field. The cover provides an electronic identification number and other information in response to the interrogation signal. Also provided is a system for making payments, comprising at least one mobile station (4) which has an associated cover (100) for providing local data transfer. The system also comprises at least one point of sale terminal or the like, which has a second transceiver for providing data transfer.