Number portability: what changes during a VoIP number port

Number portability lets a subscriber keep a telephone number when changing carriers. The visible number may stay the same while routing, carrier records, emergency associations, caller ID permissions, and SMS or fax support change.

Porting plan

1. Confirm the authorised account holder and service address.
2. Gather the current carrier record, numbers, PINs, and billing details.
3. Identify services tied to the number: IVR, fax, SMS, alarms, and emergency calling.
4. Prepare the receiving carrier route and test numbers before cutover.
5. Schedule a maintenance window and define rollback or temporary forwarding.
6. Test inbound, outbound caller ID, emergency routes, voicemail, and every dependent service.

A successful port order does not guarantee every downstream routing table has converged immediately. Monitor across multiple carriers and locations after cutover.

Related: E.164 formatting and emergency calling.