Described herein is multi-mode communications system that comprises at (east one internet network {540, 545), a mobile network (560), a platform (505) and a multi-mode terminal (575). Both the platform (505) and the terminal (575) are connectable to one of the internet networks (540, 545) and to the mobile network (560). A voice quality control module (525) is provided for determining if the voice call quality of a call to or from the terminal (575) via an internet network (540, 545) meets a predetermined minimum voice quality level. Handover between the internet network (540, 545) and mobile network (560) is initiated when the voice call quality falls below the predetermined minimum voice quality level.