Abstract: A circuit which prevents a telephone or a plurality of telephones from making unauthorized or restricted calls to specific numbers or unspecific groups of numbers. The restricted call numbers may be local or toll call. The circuit is disabled either on a call by call basis, or indefinitely by entering a user defined pass code. The circuit is programmable from any commercially available touch-tone phone. When in the call restriction mode, the circuit detects outgoing calls by detecting and decoding standard `DTMF` burst. Upon detecting the first valid tone, the circuit isolates the user from the central office equipment. The circuit then parses the first and all following DTMF bursts and compares them against preprogrammed internal lists of fixed or relative restricted numbers.