Teams Phone Numbers Mysteriously Unassigned

Copper Contributor

Over the last  2 weeks or so, we've noticed a handful of our Teams phone numbers which were assigned to users, become Unassigned.  We have no automation in place - everything move, add or change we perform with our phone numbers is manual.  The numbers in question have been assigned for months now.  It wasn't until my phone number was assigned to someone else that we realized the issue.  In order to assign a phone number that is already assigned, you'd have to delete the current user - which we certainly have not done.  Mysteriously, the phone number status changed from assigned to unassigned.  Has anyone experienced this?  We have Operator Connect through Pure-IP.  Thye don't touch our numbers once they are given to us in the Admin portal (or do they?).  My MS Premier ticket came up empty.  Apparently there are no audit logs for phone numbers, just licenses.  And we verified no change in license status at all.  

25 Replies


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Thanks Therese! I did open a case with MS. There are no logs, as it turns out, catch the history of phone number activity; though you can do so with licenses. We already verified that the licenses remained in-tact.

@dennyhanrahan Same problem. I thought I was going mad. Started 4-6 weeks ago now.

Long term users complaining their dial pads have disappeared. When I check Teams, the number has been unassigned.

I'm using Direct Routing via on-premise Session Border Controllers, so no-one else should be touching my numbers
That's very interesting...and unsettling! Did this happen with using Operator Connect? If so, who is your Operator Connect vendor? or did it happen with numbers provided directly by Microsoft? Thanks a bunch for replying!

@dennyhanrahan I'm not familiar with Operator Connect, but a quick Google shows these providers offer Session Border Controllers as a Service (SBCaaS) so our setup is similar.

We are using Session Border Controllers and Direct Routing. Our carrier is Optus.

We have reserved number ranges for each of our offices, and these number ranges are hosted by Optus. We pay Optus for our call charges (not Microsoft).

We are facing the same issue.  We do run Operator Connect but have been able to check and see there have been no changes through iPilot. It's very frustrating that there aren't activity logs to go back to on the MS side. We thought we've been going crazy since we asked MS and they said there is no way that should be happening.

Thanks MarcR727 for your feedback! I did get a root cause from Microsoft that it was a bug fix: The AD attribute OnPremLineUriManuallySet bit was false due to the bug. There was a bug in the legacy TAD cmdlet because of which assigning OC number did not set OnPremLineUriManuallySet flag.
Good to know, thanks Denny. I have a case open with Microsoft for this issue but they didn't mention that. I'll add your info to the case notes.

@wombattler Any further updates on this? We recently moved to teams calling and noticed this started happening.  Our Provider logged a job with Microsoft, but there has been no definite answer on the issue or solution. 

@BrendanNZ no further issues experienced here, after Microsoft's bug fix.

@BrendanNZ We are still seeing the issue (phone numbers randomly unassigned). I logged a case with Microsoft but then it didn't reoccur for two weeks, and they closed the case.


@wombattlergreat thanks Denny, much appreciated.  



We are only now experiencing the exact same random issue with our Teams Direct Routing.


Over the last couple of days our users have had their numbers unassigned. We can re-assign the number, however it disappears again after about 15 minutes.


We have over 360 users, all with Office E5 licenses and have been working using Teams for over 3 months.


Dialpads are now missing in Teams Applications

Audio Codes handsets have signed out

Internally Teams is working fine, however we cannot make/receive to/from external due to the numbers being unassigned


Does anyone know how to resolve the issue?

Hello @HaydenSlee,

here is Ahmed, a community visitor ;)
Let me try to help you :)

There could be a number of reasons for this, so it would be best to start by collecting some additional information to help narrow down the cause. Here are some steps you can take:

1. Check the status of your Direct Routing setup in the Microsoft Teams admin center. Go to the "Voice" section and look for any warning or error messages.

2. Check the status of your SBC (Session Border Controller) and ensure that it is running correctly. You may want to check the logs for any errors or issues.

3. Check the status of your PSTN connectivity. Make sure that all of your trunks and PSTN gateways are online and functioning correctly.

4. Check the status of your phone numbers. Make sure that all of the phone numbers you are using are correctly assigned to users and not expired or suspended.

5. Check the status of your users' devices. Make sure that all of the devices are online and functioning correctly. You may want to check the logs for any errors or issues.

Best of the best :)
Hi Ahmed,

I am not an expert however we have the below under "Voice Routes"

Priority: 1
Voice Route: XXXXXX (provided by vendor)
PSTN usage XXXXXX (same as voice route, provided by vendor)
SBc Enrolled (provided by vendor)

No errors anywhere we can see as the SBC is hosted by our vendor. We logged a ticket with said vendor and no other customers are having this issue and our environment is online and no error reporting from their end.

The vendor also has our numbers (100 number ranges) and they have confirmed the numbers are all still active.

This is happening to Windows 10 and 11 laptops as well as Audio Codes 430HD phones. (Issue is Teams number not being assigned to the employee so end user devices are not the cause)

This has all been working fine since our migration from Skype for Business in October until this week. No changes were made over the last week from the vendors side or our side. Looks like a Teams issue as this is affecting multiple users (now 100 +) within our Teams environment and have confirmed no changes or errors. Some users are still working fine with their numbers assigned, very random issue. Is there a Teams log file we can export?

Hello again@HaydenSlee


hmmm...No-One is expert; we are all still learning and supporting eachother if we can as much as we can:)

Yes you can Review the Teams event logs: You can check the Teams event logs to see if there are any errors or warning messages that may provide clues about the cause of the issue. To do this, you can use the Get-EventLog cmdlet in PowerShell to retrieve the event logs for Teams.

The Detailed steps for your reference:

1- Open the Event Viewer app in Windows.
2- Navigate to the Applications and Services Logs folder.
3- Expand the Microsoft folder, then the Office folder, and then the Teams folder.
4- Select the Operational log.
5- Use the filters and search options to find the events you are interested in.

To review the Teams event logs using PowerShell, you can follow these steps:

  1. Open a PowerShell window as an administrator.

  2. Connect to the Exchange Online PowerShell module by running the following cmdlet: Connect-ExchangeOnline

  3. Enter your Office 365 global administrator credentials when prompted.

  4. To retrieve the event logs for Teams, run the following cmdlet: Get-EventLog -LogName "Teams Event Log"

  5. To filter the event logs by a specific date range, you can use the -After and -Before parameters, like this: Get-EventLog -LogName "Teams Event Log" -After (Get-Date).AddDays(-7) -Before (Get-Date)

  6. To view a specific event log entry, you can use the Format-List cmdlet to display all the properties of the event log entry, like this: Get-EventLog -LogName "Teams Event Log" | Format-List *

  7. To export the event logs to a CSV file, you can use the Export-Csv cmdlet, like this: Get-EventLog -LogName "Teams Event Log" | Export-Csv -Path "C:\Temp\TeamsEventLogs.csv"

    You want to check for any errors or warning messages that may indicate a problem with the Teams service or any related components. Some specific things you may want to look for include:

    • Error messages indicating problems with the Teams service or related components, such as connectivity issues or issues with specific features.
    • Warning messages indicating potential issues that may require attention, such as low disk space or network connectivity problems.
    • Information messages that may provide context or additional details about the issue you are experiencing, such as details about the configuration or settings of the Teams service or related components.

      A good reference: Search the audit log for events in Microsoft Teams - Microsoft Teams | Microsoft Learn



Hi @HaydenSlee and Ahmed,
I just got back from long service leave, and the people who covered for me tell me this is still happening. In another twist, I've also started getting random users with Enterprise Voice changed to false.
I haven't seen the issue with a phone number disappearing 15 minutes after assignment though. That one is new to me, sorry.



I have even a more bizarre story all of my us numbers disappeared. Checked the logs. No record. I have an open case, but all DID are fast busy