A telephone number prefix finder provides information about a telephone number, such as whether a particular number is a landline or a cellphone and carrier to whom a number is assigned. The purpose of the prefix finder is to identify a caller or trace a call location.
The telephone number prefix is the group of three digits at the beginning of the telephone number after the area code. At one time, these prefixes followed geographic assignments, making it possible to identify a caller’s city, town or neighborhood. The portability of telephone numbers has eroded this functionality to some extent, but telephone prefix finders can still determine the origins of missed calls, where the phones were purchased and the companies providing the services.