What Is an Extension?

Example: A customer support agent might have extension 102. Colleagues can dial "102" to reach them internally, and that extension can also route inbound or outbound calls externally depending on configuration.

Creating a New Extension

1. From the main menu on the left, navigate to: "UC Admin" → "Extensions and Devices" → "Extensions"

2. Select “+ Add Extension” in the upper-right corner.

3. Complete the form with the following required information:

1. Assigned Account: Select the account this extension belongs to. This field only appears if you have not already selected an account from the main dropdown at the top right of the page.
2. Label: Enter a name used for internal and directory identification (e.g., “Front Desk”, “Sales - John”)
   
3. Extension Number: The internal number users will dial.
   
4. Local Dialing Country: (optional) Only change this if the user for this extension is in a separate country from the account default
   
   
   
   
   

4. Select “Add” in the lower-right to create the extension.

5. Once the extension is created, you’ll be redirected to a page where you can further customize it (refer to Step 3 in the Management section below).

Managing Existing Extensions

1. From the main menu on the left, navigate to: "UC Admin" → "Extensions and Devices" → "Extensions"

2. From the list of existing extensions, select the extension label or the three vertical dots on the right of the extension you wish to edit to manage it.

      

3. You'll have access to several configuration tabs:

1. General
   
1. Display Name, Description, Notes
   
2. Extension Number, Dialing Address (unique number that can be dialed from anywhere in the platform by any phone or extension)
3. Ring Time (in seconds before forwarding or voicemail)
   
4. Billing Settings (standard, low-use, virtual)
   
2. CallerID
   
1. Static Caller ID:
   
1. Outbound and Emergency Phone Numbers
   
2. Digits required to place external calls
   
3. Enable/Disable outbound dialing
   
2. Dynamic Caller ID: allows the user to select from multiple callerIDs they might want to use when dialing outbound. 
3. Call Flow
   
1. Local Dialing Country
   
2. Call Forwarding: Toggle on/off, specify destination
   
3. Do Not Ring: Temporarily disable call delivery
   
4. Simultaneous Ring: Ring other extensions/devices at the same time
   
5. Call Confirmation: Require recipient to accept call
   
6. Failover Destinations for:
   
1. No Answer
   
2. Call Rejected
   
3. Extension Offline
   
4. Voicemail
   
1. General Settings: Enable/Disable Voicemail, Timezone
   
2. Recordings: Upload/Download standard, temporary, and name greetings
   
3. Access & Security:
   
1. Authentication PIN
   
2. Require PIN for remote/self-check
   
3. Permission settings for changing greetings and transferring messages
   
4. Caller’s Experience / IVR Breakout:
   
1. Play greeting, require callback number, allow message leaving
   
2. Add “breakout” options (press key to reach another destination)
   
5. Recipient’s Experience:
   
1. Play extension number or name before message
   
2. Play timestamp or caller ID
   
6. One-Time Notifications: Notify one or more recipients after a message, with optional auto-delete
   
7. Multiple Notifications: Send different messages to different recipients
   
8. Notification Schedule: Limit voicemail delivery to specific hours
   
5. Audio / Video
   
1. Toggle to record inbound/outbound calls
   
2. Transcription for recorded calls
   
3. Select Music on Hold Album
   
4. Audio Codec and pitch shift settings
   
5. Enable/Disable Video Calling 
   
6. Advanced
   
1. SIP Username & Password
   
1. used to register a device or softphone to a VoIP phone system so it can make and receive calls
   
1. A SIP device is any phone, app, or hardware that uses the Session Initiation Protocol (SIP) to make and receive VoIP (Voice over IP) calls - in short, a SIP device connects to your phone system over the internet instead of using traditional phone lines.
2. Enable features like:
   
1. International Calling
   
2. Listen, Whisper, Barge for call supervision
   
3. CDR Tags (to label calls for easier sorting/reporting), Webhooks (for real-time integration with external systems), and Automation Triggers (e.g., notification when voicemail is left)
   
4. Custom Recording for outbound dialing
   
7. Clones
   
1. View or add Extension Clones (up to 9 allowed)
   
2. Extension clones allow multiple SIP devices to register to a single extension using unique credentials — great for using the same extension on a desk phone, softphone, and mobile app simultaneously.
   
8. Dependency Tree
1. Visual overview of where the extension is used across the system
   
2. Helps with troubleshooting and understanding call flow impact.
   

Be sure to click “Update” at the bottom of the screen to save your changes before navigating away.