Immediate Fix
To resolve the “Another account from your organization is already signed in” error immediately, you must disconnect the conflicting organizational account from your Windows system settings.
First, close all Microsoft Office applications. Navigate to Settings > Accounts > Access work or school. Find the account listed that matches the organization you are trying to sign into and select Disconnect.
Once disconnected, restart Word and attempt to sign in again. This process clears the hardware-bound token that prevents Word from accepting a new set of credentials from the same tenant.
Technical Explanation
This error occurs due to a conflict in the Microsoft 365 identity stack. Microsoft Office applications utilize a Single Sign-On (SSO) mechanism that strictly enforces a “one account per tenant” policy on local installations.
When you sign in, Windows stores an authentication token in the Web Account Manager (WAM). If you attempt to add a second account from the same organization (e.g., a shared mailbox or a secondary work account), the BrokerPlugin.exe identifies a mismatch in the “Identity” registry key and blocks the request to prevent data synchronization overlaps.
Alternative Methods
1. Clear Windows Credentials Manager
If the settings menu does not resolve the issue, you must manually purge the stored credentials. Open the Control Panel, navigate to User Accounts > Credential Manager, and select Windows Credentials.
Locate all entries starting with “MicrosoftOffice16_Data” and “mso_admed”. Expand each entry and click Remove. This forces Word to prompt for a clean authentication handshake upon the next launch.
| Method | Complexity | Effectiveness |
|---|---|---|
| Disconnect Work/School Account | Low | High |
| Credential Manager Purge | Medium | Medium |
| Registry Identity Reset | High | High |
2. Reset Office Identity via Registry
For persistent errors where the UI fails to clear the account, you can reset the Identity subkey in the Windows Registry. This will sign you out of all Office apps.
Run the following command in an administrative Command Prompt to delete the cached identity folder:
reg delete "HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity" /fAfter running this command, restart your computer. When you open Word, you will be prompted to sign in as if it were a fresh installation, bypassing the previous “another account” error.