Glossary Phone numbers
What is Number porting?
Also called lnp, local number portability, port a number, transfer phone number
Number porting is the process of transferring a phone number from one carrier to another without changing the number. In the United States it is a regulatory right rather than a favour, established by local number portability rules, which is why a carrier cannot simply refuse to release a number you pay for.
How a port actually runs
You sign a letter of authorization proving the number is yours to move. The gaining carrier submits a request to the losing carrier along with a recent bill, which is what the account details are matched against. The losing carrier either accepts and returns a firm date, or rejects it. Rejections are almost always an address or account number that does not match the record exactly, not an objection.
What to watch for
Do not cancel your old service before the port completes, because cancelling releases the number and a released number may not be recoverable. Check whether the losing carrier charges an early termination fee. And ask the gaining carrier what porting costs: IZT charges $5.00 once for a local number and $10.00 for toll-free, the difference being that toll-free ports involve a RespOrg change at the central registry.
Plan the cutover, not just the port
The port itself is usually uneventful; the surprises are around it. Decide in advance where the number should ring the moment it lands, because a number that ports successfully into an unconfigured system is functionally a dead number. Check anything that references the number outside the phone system, such as two-factor authentication, alarm lines, payment terminals and fax machines, since these are exactly what nobody remembers until they stop working. And schedule the cutover for a quiet hour rather than mid-morning.