Reassigning Phone Numbers in Microsoft Teams for Departing Employees
When someone leaves your company, you need a fast way to reclaim and reassign their Teams phone number. The steps differ based on how each number is connected to the Public Switched Telephone Network (PSTN). Here’s a real-world example—and the right tool for each scenario.
Scenario
Your organization uses Microsoft 365 Phone System. Two employees are leaving:
| User | Phone Number | PSTN Connectivity |
|---|---|---|
| User1 | 425-555-1332 | Calling Plans |
| User2 | 425-555-1334 | Direct Routing |
You need both numbers back in circulation as soon as possible.
PSTN Connectivity in Teams
- Calling Plans: Microsoft owns the number and handles all call routing.
- Direct Routing: Your company’s Session Border Controller (SBC) connects calls. You manage the number.
Step-by-Step Guide
1. User1 (Calling Plans)
With Calling Plans, the Teams admin center has all the controls you need.
- Sign in to the Microsoft Teams admin center.
- Go to Voice > Phone numbers.
- Find 425-555-1212.
- Click Unassign to remove it from User1.
- Reassign it to someone else or return it to the service number pool.
Tool: Microsoft Teams admin center
2. User2 (Direct Routing)
Direct Routing numbers live outside Microsoft’s portal. Use PowerShell to update assignments.
- Open PowerShell and connect to Teams: powershell
Connect-MicrosoftTeams - Remove the number from User2: powershell
Set-CsUser -Identity "User2" -LineURI $null - Assign the number to a new user: powershell
Set-CsUser -Identity "NewUser" -LineURI "tel:+14255551213"
Tool: Set-CsUser cmdlet
Quick Comparison
| PSTN Type | Tool | When to Use |
|---|---|---|
| Calling Plans | Microsoft Teams admin center | Fast, UI-based reassignments |
| Direct Routing | Set-CsUser PowerShell cmdlet | Scripted control over SBC routes |
By matching the right tool to each PSTN type, you’ll reclaim and reassign phone numbers with minimal downtime—and keep your new hires connected fast.
