Microsoft 365 / Outlook for Android sign-in broken after new Samsung phone – account works elsewhere

MJ Thurgood 5 Reputation points
2026-03-11T20:42:09.8366667+00:00

I am using a personal Microsoft account (Hotmail). My Microsoft account works correctly on the web and on non-Android devices. After moving to a new Samsung Galaxy S25 Ultra (Android), Microsoft 365 and Outlook for Android no longer work on this phone. Important details: - Android is fully up to date - Microsoft 365 and Outlook for Android are installed from Google Play - This same Microsoft account worked on Android in the past - I can sign in successfully at account.microsoft.com - This is NOT a password issue - This is NOT a subscription issue - This is NOT a Gmail account being used for Microsoft sign-in What appears to be happening: After the device change, Microsoft account authentication on Android fails or loops. Frontline support incorrectly told me “Microsoft 365 does not work on Android,” which is clearly false. I believe this is a Microsoft account / device registration / mobile authentication conflict that needs to be cleared or reset on the account side. Question: What is the correct way to reset or remove stale Android device authentication for a personal Microsoft account so Outlook / Microsoft 365 works again on a new phone?

Microsoft Security | Microsoft Authenticator
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  1. AI answer

    2026-03-11T20:42:29.41+00:00

    For a personal Microsoft account that works on the web but fails or loops only in Outlook / Microsoft 365 apps on a new Android phone, the supported remediation paths in the provided material are:

    1. Completely reinstall Outlook and Microsoft 365 apps on the Samsung phone
      This clears local app data, cached tokens, and device-specific state that can cause sign-in loops after a device change. Steps (Outlook example):
      1. Uninstall Outlook for Android from the phone.
      2. Uninstall any Microsoft 365 / Office apps (Word, Excel, PowerPoint, OneNote, Microsoft 365 app) that are having sign-in issues.
      3. Restart the phone.
      4. Reinstall Outlook and Microsoft 365 / Office apps from Google Play.
      5. Open Outlook, then:
        • Tap the account icon at the top next to Inbox.
        • Tap the Settings gear at the bottom.
        • Under Accounts, use Add Account (and Add Subscription if needed) to sign in with the personal Microsoft account.
      A similar Samsung scenario in the context was resolved by uninstalling and reinstalling Outlook and Teams on the phone.
    2. Use Microsoft’s sign-in helper for the personal Microsoft account
      If the issue is with the account’s sign-in configuration or a backend problem rather than the device itself, Microsoft’s sign-in helper can detect and guide through fixing account-side issues:
      • For a personal Microsoft account that cannot sign in to Outlook mobile, run the sign-in helper from the “Can’t sign in to the Outlook mobile app” guidance.
      • The helper asks for the email address or mobile number and checks for problems with the account configuration. If a problem is detected, it provides specific steps to resolve it; if not, it guides through self-help options.
    3. General mobile sign-in checks for Microsoft 365 apps
      If Outlook and Microsoft 365 apps still fail after reinstalling, verify the following from the mobile-app guidance:
      1. Confirm that the correct personal Microsoft account (the one associated with the Microsoft 365 subscription or services being used) is entered in the apps.
      2. Use a browser on the phone to sign in at the documented Microsoft 365 sign-in location to confirm that username and password work on that device as well.
      3. Ensure the Samsung device meets the documented system requirements for Microsoft 365 mobile apps (check via the Microsoft 365 resources page or the app’s Google Play listing).
    4. If Outlook mobile still cannot sign in
      • For a personal Microsoft account, continue using the sign-in helper flow from the Outlook mobile sign-in article until it either resolves the issue or directs to additional support.
      • For non-Microsoft accounts (Gmail, Yahoo, etc.) added into Outlook, the guidance is to contact the non-Microsoft provider, but in this case the account is a Microsoft personal account, so the sign-in helper is the relevant path.

    These steps (full uninstall/reinstall on the phone plus running the Microsoft sign-in helper for the personal account) are the supported ways in the provided material to clear problematic mobile sign-in state and correct account-side sign-in issues so Outlook / Microsoft 365 can authenticate again on a new Android device.

    References:

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