The most popular method is to use a reverse cell phone lookup service, such as White Pages.
Reverse lookup sites like ours at SearchQuarry.com will query a database to find the personal information of the caller. While a few sites offer these services for free, most charge a fee to view the details. Since cell phone numbers can easily be transferred between carriers and customers, reverse lookups are not always accurate, and may actually provide you with the information about the wrong person.
When they are correct, however, they are typically able to give you a complete overview of the owner, including name, address, and sometimes a background check report.
If the caller has linked their phone number to their Facebook profile, it will show up in a search.
Unfortunately, this method has drawbacks similar to those of reverse lookup services.
Numbers are often reused between carriers, and not everyone updates their Facebook profile on a regular basis.
Depending on their privacy settings, the number may not appear in searches at all.
Occasionally, it is possible to find the owner of a number through a regular search engine like Google or Bing. A cell number associated with a business or company will often be public record, but personal and residential numbers are sometimes made available as well.
Again, the results may be inaccurate as people may keep the same number while changing addresses, or the number may have been transferred to someone else.
Telemarketers frequently change their numbers to avoid detection, which can point you further in the wrong direction. It might take multiple tries, and several different search engines, before coming up with a result. Specialized deep web search engines like SearchQuarry.com may be more useful in this type of situation.