I find that you spend little on handset charge every month . Have you any trick ?   It's simple . You can use call transfer .   Is it so simple ?   Sure . You know , we spend most of our time at home or in the office every day , so I receive handset calls with the hand-free telephone , so I need pay little for receiving calls .   It's true .   Call transfer has many other advantages . When I am in places where network can't cover , such as the high building , I also use call transfer function , which transfers my calls to the hand-free telephone and I will not miss any call .   That's all ?   In hospitals or on planes , handsets will interfere with some equip-ment , so we must close our handsets . If you set call transfer , the problem will be solved . 