According to one embodiment, a telephone system includes at least a single of a first main apparatus and a second main apparatus, the first main apparatus includes a memory which stores a management table in which a plurality telephone terminals housed in the first and the second main apparatuses, respectively, and sate information showing each operation state of the plurality of telephone terminals are associated with each another, and a controller which updates the state information in the management table based on the state information transmitted from the second main apparatus, refers to the management table when an incoming call arrives, and executes incoming call control to the plurality of the telephone terminals based on the reference result, and the second main apparatus includes a transmitter which monitors transmits state information of the telephone terminals of which the operation states have changed to the first main apparatus. |