Methods and apparatus for transferring an established communication session in a telecommunications network

Measures for transferring an established communication session in a telecommunications network, the communication session being established between one of a plurality of communication clients associated with a user and a remote device associated with a remote party. At a call control system located in the signaling path for the established communication session, a communication session transfer request is received from a device associated with the user, the communication session transfer request having been generated by and transmitted from the device. Transfer of the established communication session from the one communication client in the plurality of communication clients to another communication client in the plurality of communication clients is initiated at the call control system. The transfer is conducted on the basis of a preconfigured data set, specific to the user, identifying one or more of the plurality of communication clients associated with the user.