Reverse cell phone lookup service is used to gather information about unknown numbers, missed as well as prank calls.

There are many services that claim to offer reverse cell phone lookup for free, but these services are not always work effectively.

Various companies provide up to 75 per cent of the data for free but they ask you to pay for the rest.

Some confidential directories gather cell number information from both private as well as public sources, plus from restricted mobile carrier databases. These directories also include land line, fax and unlisted number listings.

Reverse Phone Net service also makes searches for all major cell phone directories.

It should be noted here that Sprint or Verizon's official website does not present a free or paid cell phone directory.

A truly free way to do reverse cell phone lookup is to make use of search engines such as Google.