Reverse telephone directories can help you find a person's name and address based on his phone number, potentially identifying strange numbers on your phone bill or Caller ID. Some reverse phone directories charge for information, but there are several free online options, including Yahoo People Search, AnyWho and WhitePages. You can only look up a person's name and address using a land line number, not a cellphone number, unless you use a paid reverse directory service.
Enter the phone number, including the area code, in several free reverse phone directories.
Compare the results from the different reverse directories to one another and to what you already know about the number. Sometimes people change phone numbers when they move, or take their old phone number with them to a new address; the reverse directories may not all be up to date. They also may not include the names of people who live in the house but are not the head of household.
Enter the phone number in a paid reverse directory if you get no results (or contradictory, confusing results) from free directories or if you need to look up a cellphone number.
Compare the free preview of the reverse directory results to what you already know about the number. If you know that the owner of the number lives in a certain town, but the reverse directory places it in a different town, you may not want to pay for potentially inaccurate results.
Search for reviews of the reverse directory site to see if other users have found it accurate. If you feel confident that you'll receive good results, pay for the information.
Test the accuracy of several reverse phone directories by searching a phone number you already know, such as your own land line number, and seeing how accurate the results are. If you can't get accurate results with a reverse directory, you can narrow down the search somewhat by looking up the area code.