A communications system comprising: at least two Session Initiation Protocol, SIP, endpoints (102, 104) with multiple line capabilities; an audio communications device connected to each of said at least two SIP endpoints (102, 104) acting as originating or destination SIP endpoints, voice communications being carried out between said at least two SIP endpoints (102, 104) over a respective said audio communications device; a file transfer agent system (110, 112) at each of said at least two SIP endpoints (102, 104); and a File Transfer Application Agent, FTAA, application on each file transfer agent system (110, 112), each said FTAA application managing file transfers between file transfer agent systems (110, 112) responsive to file transfer requests from corresponding audio communications devices conneted to said SIP endpoints, characterized in that an appropriate key on the originating SIP endpoint (102, 104) is adapted to be activated to initiate a SIP call to the associated FTAA of said originating SIP endpoint, wherein the FTAA application on the originating file transfer agent system (110, 112) of the originating SIP endpoint is adapted to present an audible menu to the originating SIP endpoint to allow an endpoint user of said originating SIP endpoint to select files for transfer from the originating file transfer agent system (110; 112) and is further adapted to construct a SIP address of the destination file transfer agent system from the associated destination SIP endpoint after selecting of the files for transfer responsive to said audible menu wherein the originating file transfer agent system is adapted to call the destination file transfer agent system using the constructed SIP address, and wherein the originating file transfer agent system is adapted to transfer the selected file or files to the destination file transfer agent system. at least two Session Initiation Protocol, SIP, endpoints (102, 104) with multiple line capabilities; an audio communications device connected to each of said at least two SIP endpoints (102, 104) acting as originating or destination SIP endpoints, voice communications being carried out between said at least two SIP endpoints (102, 104) over a respective said audio communications device; a file transfer agent system (110, 112) at each of said at least two SIP endpoints (102, 104); and a File Transfer Application Agent, FTAA, application on each file transfer agent system (110, 112), each said FTAA application managing file transfers between file transfer agent systems (110, 112) responsive to file transfer requests from corresponding audio communications devices conneted to said SIP endpoints, characterized in that an appropriate key on the originating SIP endpoint (102, 104) is adapted to be activated to initiate a SIP call to the associated FTAA of said originating SIP endpoint, wherein the FTAA application on the originating file transfer agent system (110, 112) of the originating SIP endpoint is adapted to present an audible menu to the originating SIP endpoint to allow an endpoint user of said originating SIP endpoint to select files for transfer from the originating file transfer agent system (110; 112) and is further adapted to construct a SIP address of the destination file transfer agent system from the associated destination SIP endpoint after selecting of the files for transfer responsive to said audible menu wherein the originating file transfer agent system is adapted to call the destination file transfer agent system using the constructed SIP address, and wherein the originating file transfer agent system is adapted to transfer the selected file or files to the destination file transfer agent system.