I can't sign in to MS Teams Android app

Because every account fails on this Android phone before the password stage, clear the device’s Teams and browser authentication state and update the Android sign-in components rather than reinstalling Teams again.

Reset the device-side sign-in flow

Reinstallation alone may leave browser credentials and Microsoft accounts stored elsewhere on Android.

1. Open Settings → Apps → Teams → Storage.
2. Select Clear cache, then Clear data or Clear storage.
   This resets Teams and removes locally stored Teams data.
3. Open the phone’s default browser:
   • Chrome: menu ⋮ → Delete browsing data
   • Edge: Settings → Privacy and security → Clear browsing data
4. Clear cookies and cached files for the browser.
5. Open Google Play Store, then update:
   • Android System WebView
   • Google Chrome
   • Microsoft Teams
6. Open Settings → Accounts or Manage accounts. Remove any obsolete or duplicate Microsoft work accounts, but do not remove an actively managed corporate account unless your IT administrator approves it.
7. Restart the phone and test the personal account first.

Teams’ Android sign-in page relies on Android browser components, so stale browser state or an outdated WebView can disrupt the authentication page across multiple accounts. These steps resolved or isolated similar Android-only Teams authentication failures ^1^.

Also check Settings → System → Date and time and enable automatic date, time, and time zone. Incorrect time can prevent secure authentication; Microsoft associates this with authorization failures such as 0xCAA20003 ^2^.

Test the network and Android version

• Switch once between Wi-Fi and mobile data. If one works, the other network’s DNS, proxy, VPN, or filtering is interfering with authentication.
• Temporarily disable any VPN, ad blocker, private DNS service, or security app that filters HTTPS traffic.
• Confirm that Android is within the four most recent major Android versions, which are the versions supported by the Teams mobile client ^3^.

Since Teams installed successfully from Google Play, repeating the installation is unlikely to add useful information.

Korea versus Japan

The Korean Google Play country setting is not established as the cause of this sign-in failure. Microsoft distributes Teams for Android through Google Play, and the documented country restriction on the download page concerns Teams for personal use in China—not Korea or Japan ^4^.

A regional Play Store problem would more commonly affect finding, downloading, purchasing, or updating an app. The fact that the installed app rejects company and personal accounts at the same point is more consistent with the phone’s authentication path or network, although the error text alone cannot establish the cause.

Work-account-only checks

If the personal account starts working but company accounts still fail, contact the company’s Microsoft 365 administrator. For Android, an organization using app-based Conditional Access may require Intune Company Portal, including for some devices that are not enrolled in Intune ^5^.

Provide the administrator with:

• The exact error and any status/error code
• Phone model and Android version
• Teams version
• Approximate failure time and time zone
• Whether the account works in Teams on another device

Microsoft recommends recording the Teams status code because administrators can use it to distinguish account, network, and organizational-policy failures ^2^. If no code appears, include a screenshot with personal information obscured.

If every account still fails after the device-side reset and network test, the closest matched Android case recommends escalation: the company administrator can open Microsoft 365 admin center → Support → Help & Support so support can inspect the sign-in logs and device-specific failure ^1^.

References

1. Microsoft Teams login fails immediately after password change - Microsoft Q&A
2. Why am I having trouble signing in to Microsoft Teams? | Microsoft Support
3. Teams client system requirements
4. Download the mobile app for Microsoft Teams
5. Manage Teams for iOS and Android With Intune - Microsoft Intune