What Is A Phone Extension? How Does It Work? - Nextiva

Back to glossary VoIP Call features What is a Phone Extension?

An extension is a unique identifier of a phone or feature on a VoIP network. Some features may need an extension. Every user needs either an extension or a phone number, although they can have both.

Any phone with only an extension cannot have a unique e911 address. Instead if they dial 911, they provide the address to their default office location.

Related reading:

• VoIP Configuration Examples: 17 Dos and Don’ts Before You Set It Up

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