Desk phones
Ring a physical SIP handset directly on one of your numbers — even when SmileLine is unreachable — and understand exactly what that number gives up in return.
A desk phone line moves one of your numbers off SmileLine's call handling and onto a physical SIP handset. Calls go straight from the carrier to the phone on your desk, with SmileLine completely out of the path — so the phone keeps ringing even if SmileLine, or your internet-connected computers, are down.
That independence has a hard trade: SmileLine can no longer see the number's calls at all.
| On a desk phone line | On SmileLine |
|---|---|
| Rings your handset directly, always | Rings your team's devices via SmileLine |
| Works during a SmileLine outage | Depends on SmileLine being reachable |
| No ring groups, menus or opening hours | Full call routing |
| No voicemail, recording or AI receptionist | All included |
| Calls do not appear in call history | Every call on the timeline |
| No screen pop or patient matching | Both built in |
Moving a number to a desk phone is the practice owner's decision and takes effect for every caller. Most practices are better served keeping numbers on SmileLine and adding a backup number — the caller is then forwarded only when SmileLine can't take the call.
Turn a number into a desk phone line
You need the owner role, and the number can't be your outbound caller ID (pick a different caller ID first on Settings → Phone numbers).
Open Settings → Call routing and find the number's card.
Click Move to a desk phone… and confirm. The card switches to the desk-phone panel and shows Setting up for a minute or so.
When the panel shows the line is live, click Reveal SIP credentials. You'll see the three values every handset needs: server, username and password. Each reveal is recorded in the activity log.
Enter those values on your handset — pick your brand below for step-by-step instructions.
The settings every phone needs
Whatever the brand, the registration values are the same:
| Setting | Value |
|---|---|
| SIP server / registrar | sip.telnyx.com |
| Username / auth ID | from Reveal SIP credentials |
| Password | from Reveal SIP credentials |
| Port | 5061 with TLS (preferred) or 5060 with UDP/TCP |
| Registration expiry | 180 seconds |
| Codecs | G.711 A-law, G.711 µ-law, G.722 |
| STUN / ICE | off |
You can register more than one handset with the same credentials — they all ring together. The line carries up to two concurrent calls.
The desk-phone card checks with the carrier each time it opens whether a handset is actually registered on the line: Handset registered means it will ring; No handset is registered or last registration failed usually means a mistyped password or server — calls fall to the backup number until the phone registers. Unknown means the carrier has not confirmed a state yet.
Calls on the line count towards the practice's fair-use calling like every other Voice call: SmileLine reads the line's call records from the carrier once a day to count them.
Receiving and making calls
The line starts inbound-only: the handset receives calls immediately, but can't dial out. UK and US law require emergency numbers (999/112/911) to work from any line that can place calls, so outbound activates only after you register the handset's physical address — click Register emergency address… on the number's card. Once the carrier confirms it, the panel shows Two-way and the handset can dial out (domestic numbers only).
If the practice moves, register the new address before relying on the handset for emergency calls — responders are dispatched to the registered address.
Numbers that stay on SmileLine (the softphone, desktop app and extension) register per location instead — see Emergency calling.
If the handset goes offline
Set a Backup number on the same card. If your handsets are unplugged or lose registration, the carrier forwards callers there instead — the same safety net SmileLine-handled numbers get.
Set up your phone
Yealink
T3x, T4x and T5x series IP phones.
Grandstream
GRP26xx series IP phones.
Poly
VVX x50 and Edge E series.
Fanvil
X-series IP phones.
Cisco
68xx and 88xx multiplatform phones.
Cordless (DECT)
Yealink W-series DECT base stations.
Analogue adapter
Keep an existing analogue phone with a Grandstream HT8xx.
Moving back to SmileLine
Click Move back to SmileLine on the number's card. The handset stops ringing, the line's credentials stop working, and SmileLine answers the number again — its routing starts unconfigured, like a newly bought number, so set it up on the same page.
The move is carried out at the carrier in the background. If it keeps failing there, SmileLine stops retrying after a bounded run of attempts and parks the move in Review queue rather than failing silently — the row names the error. Click Move back to SmileLine again to retry it.