How to Create and Configure an Extension
An extension is a user or role on your phone system. Creating one takes a name, a number, and a location; Signal generates the SIP credentials and a matching voicemail box automatically. Devices, permissions, and caller ID are then attached to the extension, not the phone — so hardware can change without touching the person's setup.
Create the extension
- Go to Settings → Extensions → Create New.
- Enter the user's first and last name — or, for shared spaces, a role name ("Front Desk", "Exam Room 2") with a description.
- Choose the extension number. Keep a scheme: e.g., 1xx for one office, 2xx for the next; consistency pays off in BLF layouts and dial habits.
- Select the location (required — it drives E911 for the user's devices).
- Save.
Settings that matter most
Setting | Default | Why you'd change it |
|---|---|---|
Ring duration | 25 s | Shorter for front desks that must roll fast to backup |
Outbound caller ID | Account main number | Show a direct or department number instead |
Caller ID name | Account name | Per-user or per-role display (25-char max) |
Music on hold | Account default | Department-specific audio |
Directory visibility | Visible | Hide utility extensions from the dial-by-name directory |
SIP credentials
Signal generates a SIP username (extension + account identifier) and a random password on creation. Desk phones receive them via provisioning — you only need them when configuring a generic softphone, and they can be reset in one click if compromised (all registered devices disconnect until re-authenticated).
Bulk creation
Rolling out a full office? Use Import to create extensions from a spreadsheet, or Copy Extension to clone a configured template — copies inherit permissions and settings, not credentials.
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Last reviewed August 6, 2026. Still stuck? Contact Signal Support from your portal — include what you expected, what happened instead, and one example phone number or extension.