An unlisted phone number is a residential phone number that is not published in any phone directory or phone book provided to the general public. Since it would be irrational for a business to have an unpublished number, an unlisted phone number applies primarily to residential phone service customers that do not wish for their phone number to be available to the public. While any individual can request an unlisted phone number, it is a practice common for people who work with the general public, such as doctors, lawyers, politicians, and school teachers.

Prior to the development of more advanced phone technologies such as caller identification, there was no charge to have an unlisted phone number. However, most home phone service providers now charge a small fee to have an unlisted phone number because of the complication that it causes to maintain separation in their large databases. An unlisted phone number will not be published in public phone directories or books and will not show up on caller ID displays. Further, an unlisted phone number can not be obtained by calling information.

As with all information, phone numbers can be used for negative and illegal actions. Many companies offer to sell unpublished and unlisted phone number information to legal professionals, businesses, and individuals. For residential customers, phone services like privacy manager make it impossible for people with unlisted numbers to call a phone line with privacy services installed without first identifying themselves. While it is virtually impossible to keep a phone number completely private, having an unlisted phone number can significantly cut down on telemarketing phone calls, prank calls, and public invasion.

While anyone with existing phone service can switch a published number to an unlisted phone number, it only makes sense to acquire a new phone number before making it unlisted. Phone companies may work with consumers if there have been problems, such as harassment, that violate the law and help them to acquire a new, unlisted phone number if necessary.

For additional information on how an unlisted phone number may impact your phone service, call your local phone company.