A method of initiating a voice call via a dialer user interface on a user device in a telecommunications network is provided. The user device comprises at least a first communication client adapted to communicate via a first part of the telecommunications network and a second communication client adapted to communicate via a second, different part of the telecommunications network. The method includes, at the user device, receiving, via the dialer user interface of the user device, user input from a user of the device associated with initiating setup of a communication session, and selecting a given one of the first and second communication clients to pass the user input to for processing, whereby a communication session setup request is transmitted from the given communication client into the respective part of the telecommunications network.