PRIVATE BRANCH EXCHANGE SYSTEM

PURPOSE:To set message waiting by selecting either the telephone set of dial destination or that of transfer desitnation arbitrarily by the operation of a caller, by providing a selection means when an extension incoming function is set. CONSTITUTION:When an electronic key telephone EKT1a issues a call to an EKT1l, and the EKT1l sets extension incoming transfer on an EKT1m, the setting of the message waiting is selected on either the telephone set of the dial destination or that of the transfer destination by a key operation. In such a case, the call is analyzed by a central controller CC9, and is set at the telephone set of the transfer destination only by depressing a message waiting set key, and it is set at the telephone set of the dial destination by depressing the message waiting key following after a specific key. Thus, since it is possible to select either the telephone set of the dial destination or that of the transfer destination by the key operation of the EKT1a-1m and to set the message waiting, the operability of a private branch exchange system can be improved.