One Extension, Many Devices — Desk Phone, Mobile, and Web Together
A Signal extension registers up to ten devices simultaneously — desk phone, the mobile app, the web phone, and any additional SIP endpoints. An inbound call rings all of them at once; whichever answers takes the call, and the rest stop ringing. This is how one identity follows a person across desk, laptop, and pocket.
How simultaneous ring behaves
- All registered devices ring for the extension's ring duration (default 25 seconds), then the call follows the fallback — usually voicemail.
- Answering on one device cancels ringing everywhere else.
- Each device maintains its own registration; a dead desk phone doesn't stop the mobile app from ringing.
Adding device types
Device | How it registers |
|---|---|
Desk phone | |
Signal mobile app | Sign in with the user's portal credentials |
Signal web phone | Sign in from a supported browser — no install |
Generic SIP client | Manual entry of the extension's SIP credentials |
For generic clients, the extension's SIP username, password, and domain are shown on the extension's Softphone tab. Treat these as passwords.
Limits and control
The per-extension device limit is configurable from 1 to 10. Lower it for shared-role extensions (a front-desk line has no business registering a personal mobile), and reset the SIP password if a device is lost — resetting disconnects every registered device until they re-authenticate.
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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.