Before the invention of the computer or the age of the internet, there was already a successful reverse phone number lookup directory system in place in the United States. Although this system was mostly analog, meaning it utilized a lot of printed directory and filing system.
It was very efficient and accurate and was utilized by most law enforcement, government and private agencies around the country, with most of the information and data from telecommunication companies.
When cellular phones became popular, the current reverse phone directory database of that time had difficulty including cellular numbers into their system as different cellular carriers had separate databases and the move also faced strong opposition from the general public due to privacy reasons.
In the United States, any landline phone subscriber can have their numbers excluded from the country’s 411 directory, but they need to pay a small fee that ranges from 80 cents to 1.50 dollars. This would result in their number being “Listing Not Published” when someone calls the directory. Although online reverse phone directories have their own data gathering methods and searching within their database may still include unlisted numbers.
De-listing for cellular phones in the US is not possible, as different carriers have separate databases, which in most cases are accessed by different reverse phone lookup companies and are included in their system. Currently, reverse cellphone searches are not available in the countries public 411.
In recent years there have been reverse phone search companies that offer a reverse telephone directory for known telemarketers, and other companies which consumers can use to identify the calling company, to verify their credentials and authenticity. As technology and the internet advances, it has become relatively easy to perform reverse phone lookups through online services, there are now numerous websites that offer the service, they charge fees for membership which includes unlimited searches or small one time fees for one time phone number lookups.