A reverse telephone directory is just exactly what the name implies; it is a directory or database containing telephone numbers and the associated customer or owner information and details.
However, instead of looking for a telephone number using a person’s details, a reverse phone directory uses a telephone number to track down the owner’s details, in essence the reverse of how a directory is used. This service is also known by other names, such as criss-cross directory, gray pages, or a reverse phone lookup.
Since its inception, one of the main purposes of a reverse phone search and lookup was mainly in law enforcement and investigations. This came in handy when government and law enforcement agencies wanted to track down the origin of any request for assistance.
Reverse phone searching was mainly reserved for internal use only, but recently it has become accessible to the general public through private agencies with their own databases to conduct the searches. Most countries nowadays have a free directory service that can provide this information for free by just calling a number or through online phone directories.
The main problem with these directories is the limited information they provide about the owners, as well as not providing any information on cellular phone numbers and unlisted numbers. This is where agencies in the private sector that provides online reverse phone lookups come in handy, as they include information on cellphone numbers as well as criminal records and background check reports on telephone number owners.