For some reason I can’t log into Teams. It just says signing in error. Can anyone help please?

Question

Since the company has got us to download the authentication app I can’t log into Teams for some reason it just says signing in error. Can anyone help?

Answer 1

Hi @Cat 276

Welcome to Microsoft Q&A forum.  

I’m sorry to hear you’re experiencing sign‑in issues with Teams after setting up the Microsoft Authenticator app. I know how disruptive this can be when you need to access your work apps, and I’m here to help you troubleshoot the problem.

This type of issue often occurs when the Authenticator app hasn’t been fully set up yet, or when your account is still trying to use an older verification method that’s no longer available.

To help narrow this down, could you share the exact error message you see when trying to sign in to Teams? A screenshot (with no personal details) would be especially helpful.

In the meantime, here are a few things you can check:

1. Make sure your business account is properly added to Microsoft Authenticator

If you haven’t completed this step yet, you can follow Microsoft’s official instructions here: How to add your accounts to Microsoft Authenticator - Microsoft Support.

2. Review how to sign in using the Authenticator app

This guide may help clarify the process: Sign in using Microsoft Authenticator - Microsoft Support.

3. If you previously used Authenticator on another device

If you previously used Authenticator on another phone or tablet, the system may still be sending approvals there. Since your new device hasn’t been configured with the Authenticator yet, you're currently unable to access your account. The app remains linked to your previous device, which is why you're not receiving the authentication codes. 

• Try checking your old device if you still have it.
• If you’ve lost access to the old device, you’ll need your IT admin to reset your MFA.  

4. Contact IT admin

If you need further assistance, you can reach out to your IT administrator and share the steps outlined in the article Manage user authentication methods for Microsoft Entra multifactor authentication. This will help them assist you in resetting your MFA settings and restoring access to your account.  

  

 

 

Once this is done, you’ll be prompted to set up MFA again on your new device during your next sign-in.  

  

Please note that forum moderators do not have access to user account settings and cannot assist with logging in, resetting passwords, or changing access rights. While we do not have access to internal systems or administrative tools required to resolve account-specific or backend-related issues but we’ll continue doing our best to support you within the scope of our responsibilities.    

 

I hope this information helps. Please try the steps and let me know whether they resolve the issue. If the problem persists, we can work together to find a solution.  

As other users will also search for information in this community, your vote can significantly help those with similar inquiries quickly locate the most relevant resources. 

Thank you for your kindness and for contributing to the forum.   

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