Local number portability

Definition
Local number portability (LNP) is the process that allows a subscriber to keep their telephone number when they change service provider in their same geographic area.

Overview
Local number portability requires that carriers release their control of one of their assigned telephone numbers so customers can transfer to a competitive provider without having to change their telephone number. LNP also involves providing access to databases of telephone numbers to competing companies that allow them to determine the destination of telephone calls delivered to a local service area.