This paper describes the design and development of a phone -based remote controller for home and office automation. The circuit is designed based on the Turkish telephone standards and connected to the telephone network just like any normal telephone sets. Any tone dialing Dual Tone Multiple Frequency (DTMF) telephone set or hand -held tone dialer may be used to send commands to the control unit, and remotely control, a wide range of mains appliances in homes and offices. The designed circuit can also detect user identification number for prevent non-authorized use of the control unit. The feedback signal informs to the user about the results of commands.