Some people receive annoying phone calls from unknown callers on a frequent basis. These unknown numbers appear on our phone screens with the title "Blocked" or "Restricted." Telemarketers, salespersons and prank callers consider it safest to keep their numbers "Restricted" for making such calls. Fortunately, there are still ways to determine the identity of the person calling you.
Dial *57 on your phone. In some areas, dialling this code, after an unknown or restricted incoming call, automatically identifies the number. If this code doesn't work, ask your particular service provider for the code that works in the area where you live.
Contact your network provider and ask whether it provides the Anonymous Caller ID service. With this service, your phone will automatically check the authenticity of each call that comes on your phone. If the call comes from a restricted or unknown number, this service will force the caller to unblock the number before he can complete the call. Once the number is unblocked, you will see it on your Caller ID screen.
Contact your telephone company and inform it that you are getting unknown calls. You may be asked to note the date and the exact time of the calls so it can trace the caller. You may also be asked for your name and phone number. The company will then either contact the caller or the caller's company to tell her to stop calling.