Local number portability

Local number portability (LNP) for fixed lines, and full mobile number portability (FMNP) for mobile phone lines, refers to the ability of a "customer of record" of an existing fixed-line or mobile telephone number assigned by a local exchange carrier (LEC) to reassign the number to another carrier ("Service Provider Portability"), move it to another location ("Geographic Portability"), or change the type of service ("Service Portability"). In most cases, there are limitations to transferability with regards to geography, service area coverage, and technology. Location Portability and Service Portability are not consistently defined or deployed in the telecommunication industry.

In the United States and Canada, mobile number portability is referred to as WNP or WLNP (Wireless LNP). In the rest of the world it is referred to as mobile number portability (MNP). Wireless Number Portability is available in some parts of Africa, Asia, Australia, Latin America and most European countries including Britain; however, this relates to transferability between mobile phone lines only. Canada, South Africa and the United States are the only countries that offer full number portability transfers between both fixed lines and mobile phone lines, because mobile and fixed line numbers are mixed in the same area codes, and are billed identically for the calling party, the mobile user usually pays for incoming calls; in other countries all mobile numbers are placed in higher priced mobile-dedicated area codes and the originator of the call to the mobile phone pays for the call. The government of Hong Kong has tentatively approved fixed-mobile number portability; however, as of July 2012, this service is not yet available.

Some cellular telephone companies will charge for this conversion as a regulatory cost recovery fee.

LNP was invented by Edward Sonnenberg while working for Siemens. Though it was introduced as a tool to promote competition in the heavily monopolized wireline telecommunications industry, number portability became popular with the advent of mobile telephones, since in most countries different mobile operators are provided with different area codes and, without portability, changing one's operator would require changing one's number. Some operators, especially incumbent operators with large existing subscriber bases, have argued against portability on the grounds that providing this service incurs considerable overhead, while others argue that it prevents vendor lock-in and allows them to compete fairly on price and service. Due to this conflict of interest, number portability is usually mandated for all operators by telecommunications regulatory authorities. In the US, LNP was mandated by the Federal Communications Commission (FCC) in 1996. The mandate required all carriers in the top 100 Metropolitan Statistical Areas (MSAs) to be "LNP-capable" and port numbers to any carriers sending a BFR (bona fide request). The ability to keep a number while switching providers is thought to be attractive to consumers. It was also a major point made by CLECs (Competitive Local Exchange Carriers) preventing customers from leaving ILECs (Incumbent Local Exchange Carriers), thus hindering competition. Details regarding the reasons for LNP and how it is to be implemented can be found in the First Report and Order referenced above.

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