The ability to block an incoming call is provided free or for a slight charge by most telephone companies. Call blocking will allow you to block your telephone number from being seen on the caller's telephone ID. It also blocks callers that block their number from being seen on your telephone's caller ID and leaves a message politely informing them that you are not taking their call.
Contact your telephone company. Tell them that you would like to be able to block any telephone calls from callers who fail reveal a name and/or show "unlisted" on your phone ID when they call. Usually these are solicitors who call at all hours of the night or day trying to sell you something.
Sign up for the call-block service and dial the number your phone company uses for blocking calls. Each phone company uses their own code or numbers to active their call blocker. The number in this article used to activate blocking is star/60, but it probably is different than the number you might need to use.
Activate call blocking by pressing the star key and 60 (or your number). Listen to the instructions that follow. Set up a list of all of the personal phone numbers of people that you want to block. Add any phone numbers of those who call without revealing their phone numbers. While it takes a little time to set up call blocking, using it is simple.
Deactivating the call-block service for a specific phone number is a cinch. Use a different number after you hit the star key, as provided by your telephone company. Usually there is a third number you press when you want to automatically block the telephone number immediately while they still are on the line.
Items you will need
If your phone company does not provide the type of call block you want or need, you can buy one from the Internet by searching for "call blocking."
Make sure that you understand how to work this service. You might accidentally add a friend to be blocked list and then wonder why they do not call you.