A method of upgrading a self-service terminal (SST), such as an ATM. An SST is first identified which has (1) a screen for displaying withdrawal options usable by a customer and (2) a touch input mechanism for receiving user commands. Then the SST is modified so that it can receive user commands from a wireless telephone. The modifications may include retro-fitting the SST with a transceiver adapted to receive signals directly from a wireless telephone. Alternately, or additionally, the modifying step may include retrofitting the SST and/or a network system host with a program for enabling the SST to receive a transaction from a remote source.