Call barring is an action that prevents certain numbers from being dialed out from a telephone handset. Call barring can also block a phone from receiving calls from certain numbers and works similarly to the action of blocking calls.
The purpose of call barring is to prevent international calls or long-distance calls that may use up minutes and other phone resources from being dialed out accidentally. The service is designed to help international travelers save money by blocking international calling features.
Call barring is a GSM supplemental service available for mobile telephones. Call barring can be initiated by entering a service code that is created by the mobile phone service provider.