Abstract: An interactive data communications system comprises a plurality of subscriber stations each of which has an identification code associated therewith and an entry terminal for manually entering data in response to a broadcast signal. Each entry terminal is connectable to a transmission line, the system including switching means for selectively allowing either data or voice signals to be conveyed down the transmission line. The transmission lines are linked to a data switching mechanism which includes a plurality of voice/data multiplexers. A control station is arranged to communicate with the data switching mechanism via a data link, the control station comprising at least one host computer for processing the data entered from the various entry terminals. The invention extends to a method of establishing a data link between a subscriber station and a host station which utilizes an interactive data communications systems.