A remote control system for a hearing aid (9) comprises a mobile telephone (1) and a plug-in device (5). The mobile telephone (1) is executing hearing aid remote control software and transmitting commands to the hearing aid (9) via the plug-in device (5). The plug-in device (5) comprises means for transmitting remote control commands or audio to the hearing aid (9) wirelessly. The invention provides a system, a plug-in device and a mobile telephone.