Long distance telephone call security system

Abstract

A self-contained electronic system which may be connected to either a standard dial telephone or push-button telephone for preventing use of the telephone for unauthorized long distance or toll calls. The system permits an authorized individual to key in a pre-determined security code to disable the long distance call prohibiting circuitry. In a preferred embodiment, when a "0" or "1" is detected as the first digit actuated, thereby indicating initiation of a long distance call, the telephone is disconnected from the trunk line or central office for a pre-determined time. During this time, an authorized user may input a three-digit security code to the telephone in a pre-determined sequence within a pre-determined time which will serve to reconnect the telephone to the trunk line to permit a long distance call to be made.

Dependencies are inferred from the claim text.