You can find out the owner of a phone number with a reverse lookup service. Unlike a traditional directory, the reverse lookup allows users to query a database and get the name of the person to whom the phone is registered. However, not all reverse lookups are accurate.
Most reverse lookup services require the user to pay a fee to view search results, such as the present owner of the number or the past owners of the number. Also, because owners of cell phones can move them between carriers and transfer them to other people, the results are not guaranteed. To use a reverse lookup service, enter the full phone number into the search query field and enter any required payment information to access the records.
Another potential source of information about unknown callers is social media such as Facebook. The increased mobile support of many websites allows users to create and use social media with a mobile phone number rather than an email address. To find someone's phone number on Facebook, type the number into the search field. It's only possible to find information about the person if he has his profile set as publicly available and has the number listed on the profile.