A cordless telephone system includes a base unit connected to both a subscriber line and at least one branch telephone, and a mobile unit capable of being coupled to the base unit over a radio link. In the event that the handset of a branch telephone is switched on after a speech communication link has been established between the mobile unit and the subscriber line, an alarm may be provided to the user of the mobile unit. In addition, the user of the mobile unit may place the system in a holding state after a speech communication link has been established whereby the base unit and mobile unit maintain the speech communication link, but the mouthpiece of the mobile unit is disabled. In the event that the handset of a branch telephone is switched on, while the system is in a holding state, an alarm signal may be generated and output to a loud speaker at the mobile unit, and the mobile unit may be released from its holding state.