Large Tenant Mode creates a dependency on running manual sync's anytime there is a change on the Microsoft Tenant.
We're in the same position, using large tenant mode, where "auto-sync" is not even close to being automatic and I've had to continue using manual efforts to keep it running, which is very frustrating, especially since the limitation around large tenant mode doesn't appear to be documented anywhere in the 8x8 knowledgebase.
I had high hopes for auto-sync and have not completely lost hope, i'm even investigating moving away from large tenant mode if it removes the limitation.
De-activating user accounts in the Microsoft tenant is "standard process" so for the mechanism to not cope well with this seems like very poor design.
The other obvious gap is that nothing on the Admin Console side can be automated so as I'm sure most organisations are heavily automated on the Microsoft side, needing time sensitive human intervention to deal with sequence issues due to auto-sync is a bit of a deal breaker for us to moving forward with wider rollout.
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Jonathan Lynn
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Original Message:
Sent: 01-07-2026 08:20
From: Stephen Barrett
Subject: Teams accounts retaining number after 8x8 account deleted
Yes, Large Tenant Mode is enabled.
I processed a handful of users today and noted that on Teams they had already lost their numbers so there was no follow up activity after deleting them from 8x8.
I don't know what causes the 2 different scenarios.
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Stephen
Agilisys
UK
Original Message:
Sent: 01-06-2026 11:57
From: Jonathan Lynn
Subject: Teams accounts retaining number after 8x8 account deleted
Are you using large tenant mode?
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Jonathan Lynn
Original Message:
Sent: 01-06-2026 10:33
From: Stephen Barrett
Subject: Teams accounts retaining number after 8x8 account deleted
We've automatic user provisioning with Microsoft Entra ID active and when a user is deactivated (not deleted) in Entra, they are deactivated in 8x8 as expected.
However when the 8x8 account is deleted the number assigned is retained on Microsoft Teams side. Its not yet clear if this occurs all the time.
8x8 support advised
"When synchronization is active and a user profile is missing, that profile would need to be re‑created for the sync to function correctly.
As a best practice, ensure that the user's profile and associated services (such as phone numbers and licenses) are removed from the 8x8 application in Azure before the Entra account is disabled. This helps prevent numbers from remaining assigned in Teams after the 8x8 user is deleted."
I can't find any 8x8 article on this. Does anyone know of one?
Our policy for leavers is to deactivate Entra accounts first, for many reasons. I don't think we can make editing of the 8x8 account a first step before doing that.
The workarounds we've found to force freeing up of numbers are
Teams Admin GUI https://learn.microsoft.com/en-gb/microsoftteams/assign-change-or-remove-a-phone-number-for-a-user?tabs=assign-by-number-list#use-teams-admin-center-to-remove-a-phone-number-from-a-user
or
the Powershell commands in the resolution to this https://support-portal.8x8.com/helpcenter/viewArticle.html?d=50bbb0bf-2e23-4f94-aac0-b4f682844e4c
#8x8forMicrosoftTeams
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Stephen Barrett
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