Phone Numbers & Conferencing
Assign phone numbers to users, set up conferencing bridges for dial-in meetings, and manage service numbers for auto attendants and call queues.
Phone numbers in Teams
Phone numbers in Teams work like assigning extensions in a traditional office phone system.
There are three types: user numbers (for individual people — their direct dial), service numbers (for auto attendants and call queues — the main office number), and conferencing bridge numbers (dial-in numbers for meetings so people without Teams can join by phone).
You get numbers from Microsoft (Calling Plans), your carrier (Operator Connect), or your own SBC (Direct Routing) — then assign them to the right people and services.
Number types
| Feature | Assigned To | Source | Licence |
|---|---|---|---|
| User (subscriber) | Individual users — their direct phone number | Microsoft (Calling Plans), carrier (Operator Connect), or SBC (Direct Routing) | Teams Phone + Calling Plan (or carrier plan) |
| Service (toll) | Auto attendants, call queues — main office numbers | Microsoft or carrier — higher concurrent call capacity | Teams Phone Resource Account licence + Calling Plan (if needed) |
| Service (toll-free) | Auto attendants, call queues — 0800/1-800 numbers | Microsoft or carrier | Resource Account licence + Communication Credits (callers are free, org pays) |
| Conferencing bridge | Audio conferencing dial-in — join meetings by phone | Microsoft-provided or ported from carrier | Audio Conferencing licence (included in E5) |
Service numbers vs. user numbers: Service numbers support higher concurrent call capacity — a user’s phone number can only handle a few simultaneous calls, but a service number on a call queue can handle hundreds. Always use service numbers for auto attendants and call queues.
Provisioning phone numbers
From Microsoft (Calling Plans)
Teams admin center → Voice → Phone numbers → Add
- Choose country/region
- Select number type (User or Service)
- Select location (city/area code)
- Choose quantity
- Numbers are provisioned from Microsoft’s pool
From carrier (Operator Connect)
Numbers appear automatically in the Teams admin center after your carrier provisions them. Managed through the carrier’s portal, assigned in the Teams admin center.
Porting existing numbers
If you’re migrating from another system, you can port existing numbers to Teams:
- Submit a port order through the Teams admin center
- Provide a Letter of Authorization (LOA) from the current carrier
- Port timing varies by country/region and carrier — submit the port order in the Teams admin center and complete the required LOA or e-signature process
Assigning numbers to users
Teams admin center → Users → select user → Account → Phone number
Or via PowerShell:
Set-CsPhoneNumberAssignment -Identity "user@domain.com" -PhoneNumber "+61399991234" -PhoneNumberType DirectRoutingChanging or removing numbers
| Action | How | Impact |
|---|---|---|
| Change number | Assign a new number to the user (old number auto-unassigned) | Old number returns to available pool |
| Remove number | Clear the phone number field | User can no longer make/receive PSTN calls |
| Transfer between users | Remove from user A, assign to user B | Ensure user A doesn’t need the number first |
Audio conferencing
Audio conferencing provides dial-in phone numbers for Teams meetings — essential for participants who can’t use the Teams app:
Setting up audio conferencing
- Assign Audio Conferencing licence to meeting organisers (included in E5, add-on for E1/E3)
- Conferencing bridge numbers are auto-configured by Microsoft
- Default dial-in number is based on the organiser’s location
- Custom toll-free numbers can be added (requires Communication Credits)
Conferencing bridge settings
Teams admin center → Meetings → Conference bridges
| Setting | What It Controls |
|---|---|
| Entry/exit notifications | Tones or announcements when people join/leave |
| PIN length | Minimum PIN length for meeting organisers |
| Automatically send emails to users if their audio conferencing settings change | Notification toggle |
| Mask phone numbers | Hide caller phone numbers from other participants |
Scenario: Tara sets up conferencing at Pinnacle Corp
Pinnacle Corp has offices across APAC. Tara configures audio conferencing:
- AU toll number: +61 2 XXXX XXXX (auto-assigned, included with Audio Conferencing licence)
- AU toll-free: +61 1800 XXX XXX (added manually, requires Communication Credits)
- NZ toll: +64 9 XXX XXXX (added for NZ-based organisers)
- SG toll: +65 XXXX XXXX (added for Singapore organisers)
Each meeting invite automatically includes the organiser’s default dial-in number based on their country. International participants see all available numbers listed in the invite.
Communication Credits are loaded with $500/month to cover toll-free call costs. Tara monitors usage via the PSTN usage report.
🎬 Video walkthrough
🎬 Video coming soon
Phone Numbers & Conferencing — MS-700 Module 21
Phone Numbers & Conferencing — MS-700 Module 21
~10 minFlashcards
Knowledge Check
Pinnacle Corp's main reception auto attendant needs a published phone number that can handle 50 simultaneous incoming calls. What type of number should Tara assign?
Tara adds a toll-free number (+61 1800 XXX XXX) to Pinnacle Corp's conferencing bridge. What additional requirement must she configure?
Next up: Voice Policies & Voicemail — configure voice settings, calling policies, and voicemail for Teams Phone users.