Sign-in & Login Problems

How to Fix Microsoft 365 Multiple Accounts Sign-in Error on Mac

Rana Garcia Oct 10, 2026 869 views

Question details

Users are unable to sign in to Microsoft 365 on a shared Mac due to an error stating another organizational account is already signed in.

How to Fix Microsoft 365 Multiple Accounts Sign-in Error on Mac

Product: Microsoft 365
Device & OS: Mac
Scenario: Multiple employees using the same Mac need to sign in to their respective Microsoft 365 accounts belonging to the same tenant.
Observed behavior: Microsoft 365 displays the error message: 'Sorry, another account from your organization is already signed in on this computer.'

Before you start

Ensure you have the exact login credentials for the new account you wish to use, and verify with your IT administrator if both accounts belong to the same Microsoft 365 tenant.

Solution 1Recommended

Sign Out the Previous Organizational Account

The quickest way to resolve this issue is by manually signing out the previously logged-in Microsoft 365 account to clear the active tenant session.

A Mac computer can accept multiple Microsoft 365 accounts from different tenants, but it restricts simultaneous logins from multiple accounts belonging to the same tenant. Signing out the active user releases the lock for your organization.

Open a Microsoft Office application

Launch any Office application on your Mac, such as Microsoft Word or Excel.

Access the account menu

Click on the application name (e.g., 'Word') in the top menu bar, or click on the user profile picture in the top-left corner of the document gallery.

Sign out the current user

Select 'Sign Out' from the dropdown menu and confirm the action when prompted to remove the active session.

Sign in with the new account

Restart the Office application and click 'Sign In'. Enter the credentials for the new organizational account.

Sign Out the Previous Organizational Account

Session Cleared: Once signed out, the new user from the same organization will be able to activate Office without triggering the multi-account conflict error.

Free Microsoft Office alternative

Try WPS Office for a Hassle-Free Multi-Account Experience

Avoid tenant login conflicts and licensing restrictions entirely with WPS Office. It's a free, lightweight, and user-friendly alternative to Microsoft Office that offers seamless format compatibility without complex organizational login restrictions on shared Mac computers.

1. Download the software: Visit the official WPS Office website and download the installation package designed for Mac.
2. Install and launch: Install WPS Office on your shared Mac and open it to begin managing your documents.
3. Open your files directly: Open, edit, and save your existing Microsoft Office files locally without needing to switch organizational accounts.

Zero organizational tenant login conflicts for shared Mac computers.Fully compatible with standard Microsoft Office formats, including DOCX, XLSX, and PPTX.Lightweight installation that runs smoothly and saves Mac storage space.Familiar user interface for a seamless transition without a learning curve.

Frequently Asked Questions

Can I use two different Microsoft 365 accounts on the same Mac?

Yes, you can use multiple accounts on the same Mac, provided they belong to completely different Microsoft 365 tenants (different organizations). If both accounts belong to the same organization, the first account must be signed out before the second can sign in.

Why does Microsoft Office say another account from my organization is signed in?

Microsoft 365 enforces a licensing and security policy that prevents multiple accounts from the same organizational tenant from being actively signed into Office applications on a single Mac user profile simultaneously.

Does creating separate Mac user profiles solve this multi-account issue?

Yes. Setting up separate macOS user accounts for each employee isolates the application data and Apple Keychain. This allows each user to remain logged into their respective Microsoft 365 account on their own Mac profile without conflicting with others.

Login & Account Issues