Fix Microsoft 365 Apps on Mac Repeatedly Asking for Sign-In
Question details
Users experience repeated sign-in prompts from Microsoft 365 applications on Mac, which interrupts workflow and prevents proper document synchronization.
- Product
- Microsoft 365 Apps
- Device & OS
- Mac
- Scenario
- Using Microsoft 365 desktop apps like Word, Excel, and Outlook after cached credentials expire or when switching user accounts.
- Observed behavior
- The applications repeatedly request the user to sign in, resulting in continuous login loops, document upload failures, and OneDrive synchronization errors.
Ensure you know your current Microsoft account password, and save any currently open offline work locally on your Mac to prevent data loss before clearing your login credentials.
Clear Outdated Microsoft Credentials from Keychain Access
Use this method to remove expired or corrupted login data, which is the most common cause of repeated sign-in prompts on macOS.
macOS stores your login tokens securely in Keychain Access. When these tokens expire or become corrupted, Microsoft 365 apps fail to authenticate automatically in the background, triggering endless login prompts.
Open any Microsoft 365 app such as Word or Excel. Click on the app's name in the top Mac menu bar, select 'Sign Out', and then fully quit all running Microsoft applications.
Open Finder on your Mac, navigate to Applications > Utilities, and double-click 'Keychain Access' to open the password management utility.
In the Keychain Access search bar at the top right, type 'Microsoft'. Select all entries related to Microsoft Office or your Microsoft account, right-click them, and choose 'Delete'.
Restart your Mac to apply the changes. Open Word or Excel and enter your Microsoft account credentials to generate a fresh, uncorrupted login token.
Disable Office Application Sync in OneDrive
If the sign-in loop is accompanied by upload errors and you do not require real-time co-authoring, disabling this OneDrive setting can resolve the synchronization conflict.
Tired of login issues? Try WPS Office for Mac
If repeated sign-in prompts, synchronization errors, and subscription checks are disrupting your productivity, WPS Office offers a free, lightweight, and stable alternative. Enjoy seamless local document editing without forced cloud logins, wrapped in a familiar interface.
- 1. Download the Mac installer: Visit the WPS official website and download the free WPS Office installer designed specifically for macOS.
- 2. Install and launch: Follow the simple installation prompts and launch the application to access the all-in-one workspace.
- 3. Open your files directly: Open your existing Word, Excel, or PowerPoint files without worrying about formatting changes or mandatory account logins.
Frequently Asked Questions
Why does Microsoft 365 keep asking me to sign in on my Mac?
This typically occurs when the cached login credentials stored in your Mac's Keychain Access become expired, corrupted, or fall out of sync with your current Microsoft account status.
Will clearing my Microsoft credentials from Keychain delete my files?
No, removing cached credentials from Keychain Access only clears your stored login data. Your documents, spreadsheets, and files stored locally or on OneDrive remain completely intact and unaffected.
How do I know if OneDrive is causing the sign-in loop?
If your sign-in prompts are accompanied by specific file upload failures, sync errors, or notifications stating that your document cannot be saved to the server, the issue is likely tied to OneDrive's Office file syncing mechanism.
Can I use Microsoft Office apps offline to bypass the login prompt?
Microsoft 365 periodically requires an internet connection and active authentication to verify your subscription status. If you remain offline for too long (usually 30 days) or if the cached token is invalid, the apps will restrict editing features until you sign in again.
