A telephone and a method of controlling thereof for cost control are disclosed. The telephone includes a processor that controls operation of the telephone, and a memory which stores user defined parameters used to control this operation. The parameters include call allowance categories and numbers,...http://www.google.co.uk/patents/US6169790?utm_source=gb-gplus-sharePatent US6169790 - Method of restricting the duration of telephone calls and telephone implementing such a method 
