Teams application won't authenticate on phone

Hello @Oliver, Brenda,

Good day! I hope you are doing well.

Based on your description, I understand that you’re unable to sign in to the Microsoft Teams app on your phone. The app reaches the authentication screen but either does not send a verification code or continues spinning when signing in with your ID and password, despite multiple troubleshooting steps already taken. At the same time, you’re able to access Outlook without any issues. Please let me know if I misunderstood any part of your issue or if there are additional details you’d like to share.

To help us provide the most accurate and effective solution for your issue, could you share a bit more detail about your setup:

• Are you using an Android or iPhone, and what is the OS version?
• Does Teams sign in successfully if you try via a mobile browser (https://teams.cloud.microsoft) on the same phone?
• What multi‑factor authentication (MFA) method is configured on your account (SMS, Microsoft Authenticator, Email,...)? Is the authentication method working as expected for other Microsoft apps?
• Are you connected to Wi‑Fi, mobile data, or a VPN when attempting to sign in?
• Is this a work‑managed device or a personal phone, and do you have Company Portal / Intune installed?
• Did this issue start after a recent phone OS or security update?

This additional context will help us understand your environment and confirm whether this is related to device configuration, authentication, or organizational policy, so we can tailor the guidance to resolve the issue effectively.

I apologize if I could not jump straight to a solution. I want to avoid suggesting anything that might be inaccurate or unhelpful. Once I have the details above, I’ll be able to assist you more effectively and guide you toward the right resolution.

Looking forward to your response so we can get this sorted out for you together.

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Follow these steps to troubleshoot Teams authentication on the phone, based on similar mobile sign-in and Authenticator issues:

1. Verify account and password work outside the app
   • In a mobile browser, go to the normal Microsoft 365 sign-in page and sign in with the same work/school account used in Teams.
   • If sign-in fails there, reset the password or contact the organization’s IT admin.
2. Check Microsoft Authenticator / MFA path
   Since the Teams screen is “spinning” at the authentication step and no code/prompt arrives, the issue is likely with the MFA path:
   • Open the Microsoft Authenticator app directly and make sure it opens and is unlocked. If it shows as locked, unlock it and try Teams again.
   • Ensure notifications are enabled for Authenticator on the phone so prompts are not silenced.
   • Confirm the phone has a stable internet connection (Wi‑Fi or mobile data) and try switching between them.
   • Make sure the Authenticator app is updated to the latest version from the app store.
   • Check the device’s date and time settings are correct and set to automatic.
   • If Authenticator is stuck or won’t unlock, uninstall and reinstall it, then re-register the account following the organization’s MFA setup process.
3. If using SMS/voice codes instead of Authenticator
   • Check for any silent or missed text messages with codes.
   • Confirm the phone has signal and can receive SMS/voice calls.
   • Retry sign-in and explicitly choose the SMS/phone option if available.
4. General Teams/mobile sign-in checks
   • Confirm the device meets app system requirements and that Teams is updated to the latest version from the app store.
   • Make sure the correct work or school account is used (not a personal Microsoft account) when signing into Teams.
   • If the organization requires VPN or specific network locations, connect to that network/VPN before opening Teams.
5. If authentication still does not complete
   • If the message “Authentication did not complete” or similar appears, it is almost always one of: locked Authenticator app, silent notifications, outdated app, network issues, or incorrect date/time. Re-check each of these.
   • If all steps above fail and the browser sign-in works, contact the organization’s IT admin to check for conditional access policies, device compliance, or risk-based sign-in challenges that could be blocking mobile sign-in.

References:

• Authentication did not complete
• Troubleshoot problems with Microsoft Authenticator
• What you can do in the Microsoft 365 apps on mobile devices with a Microsoft 365 subscription
• Why am I having trouble signing in to Microsoft Teams?
• Restore your access to Microsoft Teams