How to Fix “Another Account from Your Organization Is Already Signed In” in Microsoft 365

Seeing “Another account from your organization is already signed in on this computer” while activating Microsoft 365? Office usually has a second work or school identity cached from the same organization. Sign out everywhere first, restart, and sign in with the account that owns the Microsoft 365 license. If that does not work, use the Windows OneAuth or Mac reset instructions below.

Why this Microsoft 365 sign-in error appears

Word, Excel, Outlook, and other Microsoft 365 apps keep local identity and activation data. The message can be legitimate when another account from the same Microsoft Entra tenant is already signed in. It can also be caused by stale credentials from a previous user, a Windows work account that no longer matches the Office license, or a damaged cached sign-in record.

Fix 1: Sign out of all Microsoft 365 apps

1. Open Word or Excel and choose File → Account.
2. Sign out of every work or school account you do not want to use.
3. Close Word, Excel, Outlook, Teams, OneDrive, and other Microsoft 365 apps.
4. Restart the computer.
5. Open Word and sign in with the account that has the Microsoft 365 Apps license.

If this works, stop here. If the same error returns, continue to the device-specific instructions.

Windows: find and edit the OneAuth JSON account file

The Windows account store is normally located at:

%LOCALAPPDATA%\Microsoft\OneAuth\accounts

Paste that path into the File Explorer address bar. The folder contains one or more GUID-named files. These are JSON-style account records; they are not normal documents that you should edit casually.

Back up the JSON folder first

1. Close every Microsoft 365 app.
2. Copy the entire accounts folder to your Desktop or another protected backup location.
3. If something goes wrong, close Office and restore the original files from that backup.

How to disable or enable Office for one account

Open the GUID files in Notepad and inspect account_hints. This helps you identify which file belongs to the account you want to keep and which file belongs to the stale account.

In the stale account’s file, find association_status. For Microsoft 365 activation, the relevant setting is com.microsoft.Office:

"association_status": "{"com.microsoft.Office":"associated","com.microsoft.Outlook":"associated"}"

Enable/keep Office associated: the value is associated. Disable Office for that cached account: change only the Office value to disassociated:

"association_status": "{"com.microsoft.Office":"disassociated","com.microsoft.Outlook":"associated"}"

1. Save the edited file in Notepad.
2. Do not change account_hints or unrelated application entries.
3. Open Word and try activation again.

If you cannot confidently identify the right file, do not guess. Ask your Microsoft 365 administrator to confirm the account before editing it.

Windows fallback: clear OneAuth and IdentityCache

Use this only after signing out and trying the targeted JSON association change. The two folders are:

%LOCALAPPDATA%\Microsoft\OneAuth
%LOCALAPPDATA%\Microsoft\IdentityCache

1. Close Word, Excel, Outlook, Teams, OneDrive, and other Microsoft 365 processes.
2. Back up both folders.
3. Remove the contents of the OneAuth and IdentityCache folders in File Explorer.
4. Restart Windows and sign in again with the licensed account.

For the Mac procedure, jump to Reset Microsoft 365 credentials on Mac. For the official Windows troubleshooting sequence, see Microsoft’s activation guidance.

Mac: reset Microsoft 365 OneAuth credentials

Close Word, Excel, Outlook, and other Microsoft 365 apps. Open Terminal and run:

defaults write com.microsoft.Word ResetOneAuthCreds -bool YES

This command changes Word’s OneAuth reset preference for the current Mac user. Open Word again and continue activation. You normally do not need administrator rights for this command, but organization-managed Macs may restrict sign-in settings.

Need the Windows path instead? Jump back to the Windows OneAuth JSON instructions or read the Windows cache fallback.

Other checks before contacting IT

• Check Settings → Accounts → Access work or school for an old account, and disconnect it only with your organization’s approval.
• Ask an administrator to confirm that your user has a Microsoft 365 Apps license.
• Install Windows and Microsoft 365 updates, then restart.
• Ask IT to check whether antivirus, proxy, firewall, or VPN rules block Microsoft.AAD.BrokerPlugin_cw5n1h2txyewy. Do not permanently weaken security.
• If only one Windows profile is affected, test a new profile with administrator approval.

Verify that activation is fixed

• Open Word and go to File → Account.
• Confirm that the intended work or school account is listed.
• Confirm that Office reports an activated or licensed product.
• Create, save, close, and reopen a test document.

If the error still appears

The remaining cause may be tenant licensing, a disabled device, a managed security policy, or a damaged Windows profile. Microsoft’s troubleshooting article covers license assignment, device status, BrokerPlugin access, and the Microsoft 365 sign-in troubleshooter in Get Help.

For related tutorials, visit the Microsoft Office guides on XScript.

Frequently asked questions

Can two Microsoft 365 accounts be used on one computer?

Yes, but activation and organization policies can restrict which work or school identity is associated with the installed Office apps.

Will clearing OneAuth delete my documents?

It removes cached sign-in data, not documents in OneDrive or local folders. It can still sign you out, so back up first.

Do I need administrator rights?

Normal sign-out and the Mac reset command use the current user account. Managed Windows devices may require administrator or IT approval.

Official references

• Microsoft Learn: Another account from your organization is already signed in
• Microsoft Support: About accounts in Office