A communication terminal having one or more one-touch-dial buttons simplifies operations needed for registration of destination data such as phone numbers or mail addresses. A communication terminal (e.g., a cellular phone) having one or more one-touch-dial buttons includes a destination-data registration unit (e.g., a phone-directory database) that allows destination data such as phone numbers or mail addresses to be registered therein, a one-touch-dial registration unit that allows destination data to be registered therein so as to be associated with the one or more one-touch-dial buttons, and a control unit that, in response to an operation of the one or more one-touch-dial buttons, determines whether destination data has been registered in the one-touch-dial registration unit or the destination-data registration unit, and that outputs a result of the determination and a query message regarding registration of the destination data.