previous employer Teams will not log out

Remove the former employer from Teams → Settings → Accounts and orgs first; if it is the account’s Home organization, only the former employer’s administrator can remove it, but its saved sign-in can still be disconnected from your device.

1. Leave the former organization in Teams

If you use Teams for personal use:

1. Open Teams → Settings → Accounts and orgs.
2. Find the former employer and select Leave.
3. A browser opens. Under Organizations, select Leave, then confirm.
4. Allow a few hours for the change to synchronize, then sign out of Teams and sign back in. ^1^

Alternatively, sign in to the My Account portal, open Organizations, and select Leave organization beside the former employer.

Be aware that leaving deletes your data in that organization and cannot be undone without a new invitation. You can leave an organization listed under Other organizations, but not the Home organization that owns the work account. ^2^

2. Disconnect the former work account from Windows

If Teams keeps selecting or reopening the old account:

1. Close Teams.
2. Open Windows Settings → Accounts → Access work or school.
3. Expand the former employer’s account.
4. Select Disconnect, then Yes.
5. Restart Teams and sign in with the account you now use.

Disconnecting removes that organization’s sign-in information and data from the computer; it does not delete the employer-owned account itself. ^3^

Also check Settings → Accounts → Email & accounts. If the old address appears under accounts used by apps, remove it there when that option is available.

If the account cannot be removed

• It is shown as the Home organization: You cannot leave it yourself. Contact the former employer’s Microsoft 365/Entra administrator and request removal or deletion of the account.
• The employer no longer exists: Disconnecting it from Windows removes its local sign-in association, but it does not remove the cloud account from the former tenant.
• Android with Company Portal: If the phone was enrolled in the former employer’s management, the device must be removed from Company Portal and unenrolled first. If that is no longer possible because the account is disabled, the former employer’s IT administrator must remove the enrollment. ^4^
• Mobile without device management: In Teams, open the account/profile list, select the old account, and choose Sign out. Then remove that Microsoft account from the phone’s system Settings → Accounts. ^5^

References

1. Leave a work or school organization in Microsoft Teams for personal use | Microsoft Support
2. Manage organizations for a work or school account in the My Account portal | Microsoft Support
3. Manage User Accounts in Windows | Microsoft Support
4. Can't add new working account for Teams App on Android - Microsoft Q&A
5. How to remove account no longer in use via Mobile appon cell phone - Microsoft Q&A