Number Portability

From NENA Knowledge Base

Number Portability enables customers in the United States to keep their telephone number when switching Service Providers.

Related Terms:

Alternate Number, Call Forward Number

Used in Interim Number Portability (INP), the caller's original telephone number which is call forwarded to the new carrier's telephone number.

Donor Company

The Service Provider currently responsible for an end user’s telephone service prior to the migration of the telephone number to another Service Provider.

GNP (Geographic Number Portability)

A form of telephone number portability, where a telephone number may be ported outside its originally assigned rate center (e.g., across LATA boundaries, or to another state). This is different from Local Number Portability (LNP) where the telephone number must be reused within the same rate center.

INP (Interim Number Portability)

The practice of moving a customer to a new carrier using a new telephone number, with the old telephone number forwarded to the new telephone number.

LNP (Local Number Portability)

A process by which a telephone number may be reassigned from one Local Exchange Carrier to another.

Local NPAC (Number Portability Administration Center) Database

The eight (8) regional Number Portability Administration Center Databases which contain current Service Provider switching specific information about TNs involved in porting activity.

LSMS (Local Service Management System) Database

The LSP (Local Service Provider) owned network database which holds down-loaded ported number information. The NPAC (Number Portability Administration Center) SMS (service management system) downloads information to the LSMS; the LSMS supplies porting data to the SCP (service control point) used for the routing of telephone calls.


The action to transfer an unlocked telephone number from the donor company to the recipient company.

NPAC (Number Portability Administration Center)

Porting data is available throughout the U.S. from the NPAC database via IVR access. Throughout the 02-011 document, referral to access porting data, does NOT mean IVR access.

Recipient Company

The new Service Provider responsible for the end user’s telephone service and E9‑1‑1 data after the migration of the telephone number from a Donor Service Provider.

Remote Call Forwarding

As utilized within Interim Number Portability, a permanent call forwarding feature that allows a call to one Directory Number to be automatically advanced to a Directory Number of another Local Exchange Carrier.


The action required by a 9-1-1 Database Management System Provider, upon notification from a Donor Company, that makes the end user's telephone number record available for the Recipient Company to replace the customer details and Company ID.

Relevant NENA Documents

NENA-STA-020, NENA Standard for 9-1-1 Call Processing