Create extensions so callers can reach your employees.


  • Assign extensions for employees and devices to enable inbound and outbound calling
  • Set up extensions for IP phones, mobile phones and softphones
  • Transfer calls between extensions
  • Specify outbound caller ID for extensions
  • Forward incoming calls to multiple extensions simultaneously or in sequential order
  • Use the same extension for multiple devices so they ring together, or assign unique extensions to customize ring patterns


  • Free unlimited extensions with all plans
  • Instant setup through the Telzio website
  • Personalized voicemails and hold music
  • Free calling between extensions, even across different physical locations

How to Create Extensions

Frequently Asked Questions About Extensions

How do I set up an extension?

To assign an extension to an employee or phone, first create a user. You can create, edit and delete users on the Users page in your Telzio account. See How to Create a User for more help.

How do I set up an IP phone?

To set up an IP phone to enable inbound and outbound calling, first you need to create a user. Once you create a user, you will get the login credentials needed to log into the IP phone. See our support pages for help on setting up IP phones.

How do I set up voicemail for an extension?

You can access voicemail settings by dialing the three-digit extension directly into the phone.