Radio telephone

A cellular radio telephone comprises a mobile cellular telephone (1) adapted to have a handset (5′) containing a number assignment module, i.e. a NAM (19), removably connected thereto. The mobile telephone (1) has a microprocessor (4) which can access the information stored in the NAM (19) of the handset (5′) either directly or via a memory 16 whereby the mobile automatically assumes the telephone number of the handset when connected to the mobile telephone (1). Hence the same mobile telephone may be used as a host at different times by any number of subscribers having their own handsets. Each subscriber will be able to receive his own calls and the charges for using the system can be levied to the appropriate subscriber's account.