Alarm monitoring system

Alarm monitor system 20 has in a domestic house 21, a telephone receiver unit 22 and line 23. Alarm handset unit 24 is connected, via a two-way connector, into telephone line 23 such that, when alarm button 25 is pressed, an alarm call is made to a call centre 26 permanently manned by operators 27 who have access to a databank 28 of subscriber information. When an alarm call is received at the call station 26 and compiler 29 outputs the subscriber information from databank 28, the telephone call to the subscriber is made automatically by a transmit unit, so that the process is started immediately. The transmit unit also passes on the alarm call and subscriber information SI to operator 27 and simultaneously adds the operator 27 into the telephone call made to the subscriber. If the telephone call is answered, the operator 27 asks for a security number code. If an incorrect number code or name is given, the Police is alerted.