Your team
Extensions: short internal numbers for your team
Give each person or phone a 3 or 4 digit extension, assign it to a user, choose the device type, and call each other free anywhere in the world.
Which plans include it
Included on Growth and above. On Free Trial, Entry, Plus you can add it on its own at £2.95 a month from Features & add-ons.
What it means
An extension is a short internal number (e.g. 204). Calls between extensions stay inside your system, so they are free and work the same whether your colleague is next door or abroad.
What it does
- Creates extensions (auto-numbered if you leave the number blank).
- Assigns each to a user and a device type: Softphone, Desk Phone, Mobile or Fax.
- Labels them, adds notes, and switches them on or off.
- Makes internal calling and transfers by extension possible.
Every part of the page
- Total Extensions
- How many are configured.
- Extension list
- Ext., Label, Assigned To, Device, Status, Actions.
- Extension Number
- 3 or 4 digits. Leave blank to auto-assign.
- Label / Name
- E.g. "Reception" or "Sarah — Sales".
- Assign to User
- Links the extension to a dashboard user so it rings their softphone and apps.
- Device Type
- Softphone, Desk Phone, Mobile or Fax.
- Active
- Untick to disable without deleting.
How to use it
Give a new starter an extension
- Create their login on Users first.
- Press "Add Extension".
- Leave the number blank (auto) or type e.g. 205.
- Label "Priya — Accounts", assign to Priya, Device Softphone.
- Save. Priya can now be dialled on 205.
Examples
Simple numbering
Reception 200, Sales 201–209, Accounts 210–219. Easy for staff to remember and for callers to be told "ask for extension 210".
Two offices, one system
Staff in London and Glasgow call each other on extensions for free, as if they were in the same building.
Recommended settings
- ★Pick a pattern and stick to it: 2xx sales, 3xx support, 4xx accounts.
- ★Use 3 digits unless you will ever have more than about 100 people.
- ★Assign every extension to a user, so its calls reach their apps and voicemail.
Abbreviations on this page
- Ext. — Extension
- A short internal number (usually 3 or 4 digits) for each person or phone. Calls between extensions are free and never leave your system.
- Example: Dial 204 to reach the warehouse.
- Softphone — Software phone
- A phone that is an app or a browser tab rather than a handset on a desk.
- Example: Taking calls on your laptop with a headset uses a softphone instead of a desk phone.
- SIP — Session Initiation Protocol
- The standard language internet phones use to make and receive calls. Desk phones and apps "register" to your account with SIP.
- Example: A desk phone or app signs in to your account using SIP, with a username, password and server address.
Questions
Are calls between extensions free?+
Yes. They never touch the public phone network.
Which plans include extensions?+
Growth and above. On lower plans they can be added on their own as Internal extensions.
Can I use a desk phone?+
Yes — set Device Type to Desk Phone and contact support for the phone's connection details.
Related help
Already a customer? Open this page in your dashboard: Extensions. New to Silux Call? See the plans or start a free trial.