You may get calls on your landline or mobile phone from unknown numbers that you refuse to answer. If a number is not blocked, check for its validity to determine whether you should return the call. This is also useful if you are being harassed or threatened by an unknown caller, or even by prank callers. With the use of phone-validity websites, determine the location of the caller as well as his mobile phone or landline servicing company.
Navigate to a reverse search website or a phone number-validating website such as Phone Validator or US Search.
Locate the search box on the website and enter the desired phone number, including the three-digit area code. You may have to enter dashes between the numbers on some websites.
Select and click on the "Search" button to perform the search and redirect to the results page.
Review the results to determine information about the caller, such as the caller's location and service provider.