Is it possible to order a phone book that contains cellphone numbers?

Under U.S. law, cellphone numbers are deemed to be private information and cannot be listed in a general phone book. However, many online sites provide look-up services for numbers, also known as reverse look-ups, and some also provide paid-for services for finding cell numbers from individuals' other information.

Cellphone numbers are only listed if they have been made public in some way such as by prior publication on a website or social media forum. Online services that perform cellphone look-ups therefore trawl publicly available sites to try to associate a number with a person's other details. This is not guaranteed to produce a correct result, so it is best to be wary when paying for such services.