What is Local Number Portability?
Local Number Portability (LNP) is the ability of a telephone customer in the U.S. to retain their local phone number if they switch to another local telephone service provider.
It is the ability to transfer either an existing fixed-line or mobile telephone number assigned by a local exchange carrier (LEC) and reassign it to another carrier. In most cases, there are limitations to transferability with regards to geography, service area coverage and technology.
The Telecommunications Act of 1996 required that LECs in the 100 largest metropolitan markets provide this capability by the end of 1998. The idea is that by removing the personal inconvenience of having to get a new phone number when changing service providers, competition among providers will be increased. LNP is one of the prices that local carriers must pay in order to be allowed to compete in the long-distance market.