A method of transferring an established communication session in a telecommunications network, the communication session being established between one communication client of a plurality of communication clients (710, 712, 910) associated with a user and a remote device associated with a remote party, the method comprising, at a call control system located in the signalling path for the established communication session: in response to the establishment of the communication session between the one communication client and the remote device, transmitting, to another communication client of the plurality of communication clients (710, 712, 910), a notification that the communication session is currently being conducted between the one communication client and the remote device; receiving, from a device associated with the user and after the transmitting of the notification, a communication session transfer request, the communication session transfer request having been generated by and transmitted from the device; initiating (11d, 11e) transfer of the established communication session from the one communication client of the plurality of communication clients (710, 712, 910) to the another communication client of the plurality of communication clients (710, 712, 910), wherein the one communication client is located on the device and the another communication client is located on a further device associated with the user; and transmitting, after the transmission of the notification to the another communication client, a command to the further device to configure itself into an auto-answer mode in relation to the initiated communication session transfer, wherein the command comprises an identifier for the another communication client on the further device which is to enter an auto-answer mode in relation to the initiated communication session transfer, the transfer being conducted on the basis of a preconfigured data set, specific to the user, identifying one or more of the plurality of communication clients (710, 712, 910) associated with the user. in response to the establishment of the communication session between the one communication client and the remote device, transmitting, to another communication client of the plurality of communication clients (710, 712, 910), a notification that the communication session is currently being conducted between the one communication client and the remote device; receiving, from a device associated with the user and after the transmitting of the notification, a communication session transfer request, the communication session transfer request having been generated by and transmitted from the device; initiating (11d, 11e) transfer of the established communication session from the one communication client of the plurality of communication clients (710, 712, 910) to the another communication client of the plurality of communication clients (710, 712, 910), wherein the one communication client is located on the device and the another communication client is located on a further device associated with the user; and transmitting, after the transmission of the notification to the another communication client, a command to the further device to configure itself into an auto-answer mode in relation to the initiated communication session transfer, wherein the command comprises an identifier for the another communication client on the further device which is to enter an auto-answer mode in relation to the initiated communication session transfer, the transfer being conducted on the basis of a preconfigured data set, specific to the user, identifying one or more of the plurality of communication clients (710, 712, 910) associated with the user.