Accessory device for a portable radio telephone

The invention relates to an auxiliary device for a mobile telephone (1) in a mobile telephone network operated with a call channel and a separate data channel, the additional device for calling information from an information center (8) which communicates with the user of the mobile telephone (1) by voice output, is provided and includes a holder (2) for the connection of the mobile telephone (1). According to the invention, it is proposed that an electronic unit (3) is provided, which has a receiver (4) for determining the geographical position of the additional device, which by pressing a button (V) of a key input unit (11) the position to the information center ( 8) and receives from there relevant information on the data channel.