How can I fix a bug that keeps me from accessing another Teams site?

Question

Background

I have a Teams account at my institution.

I require access to another institution's Teams site, because I am part of a multi-institution committee. I'll refer to them as B.

Email address system update

When I first joined my institution, I was given an email address based on an old system (; not Microsoft). Institution B recorded my email as such.

When the new system with Microsoft was activated, my email was automatically transformed. When Teams arrived, I accessed it with my new Microsoft account.

When Institution B started on Teams, they used my non-Microsoft email to invite me to their Teams site, which (because my institution had transformed the accounts in the back end) did get sent to my current Outlook and I was able to join the Teams site.

MFA bug

My institution has had Multi-Factor Authentication (MFA) activated, and I use the Authenticator app with my Microsoft account.

Institution B has also recently activated MFA, but because they originally used my non-Microsoft email to invite me to their Teams, I have no way to access the MFA because it is not linked with my currently Microsoft account. When attempting to sign in to their Teams site, I can see that a notification is sent to my old non-Microsoft account, which I have no way to access because it has been discontinued.

Solutions attempted

• I have attempted to fix this with the IT department of Institution A and Institution B, with no success.
• I have asked them to delete my old email address and add my new one, with no success.
• I have created a new personal Outlook account not affiliated with my institution and asked them to add me using it. However, I cannot seem to get MFA codes sent to my device using this account even after adding it in to my Authenticator app.

I'm all out of ideas. I can't access this Teams site or any of the documents.

Answer 1

Hi @Cassandra Lamontagne,

Welcome to the Microsoft Q&A forum.

Thank you for contacting us. I would like to provide you with the following information:

I understand that you are using a Microsoft account to receive MFA verification codes when signing in. However, it is possible that Organization B has unintentionally linked your MFA to an old account (which is no longer active), which is why you are unable to receive the verification code.

To resolve this issue, please contact the IT department of Organization B and request their assistance in resetting MFA for your account.

You may provide them with the following steps:

Step 1: Go to https://entra.microsoft.com

Step 2: Select Users → All users → click on your account name

Step 3: Select Authentication methods → click Require re-register authentication methods

After the IT department of Organization B completes the steps above, the next time you sign in, you will be prompted to set up MFA again for your account. At that point, please reconfigure MFA using your new account.

I hope this information is helpful. Please follow the steps above and let me know the result. If the issue is not resolved, we can continue working together to address it.

Thank you for your patience and understanding. If you have any questions or need further assistance, please feel free to share them in the comments so I can continue to support you.

I look forward to continuing the conversation.

---

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment". 

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread

Answer 2

To resolve the issue accessing the Teams site of Institution B due to the MFA complications, you can follow these steps:

1. Contact IT Support Again: Since both institutions are involved, it might be beneficial to have a joint meeting with the IT departments of both Institution A and Institution B. Explain the situation clearly, emphasizing the need for your new Microsoft account to be linked to the Teams site at Institution B.
2. Request a New Invitation: Ask Institution B to send you a new invitation to join their Teams site using your current Microsoft email address. This may require them to remove your old email from their system first.
3. MFA Reset: If Institution B cannot send a new invitation, request them to reset your MFA settings associated with their Teams. This would allow you to set up MFA again using your current Microsoft account. They can do this through their admin settings in the Microsoft Entra Admin Center.
4. Check Guest Access Settings: If you are being treated as an external user, the administrator at Institution B needs to ensure that guest access is enabled in their Teams settings. They may need to manually add you as a guest user in their Azure Active Directory.
5. Use Alternative Sign-in Methods: If possible, see if there are alternative sign-in methods available for accessing the Teams site that do not require MFA, at least temporarily, until the issue is resolved.
6. Documentation Review: Review the documentation related to guest access and MFA issues in Teams to ensure all settings are correctly configured on both ends.

By taking these steps, you should be able to resolve the access issue and gain entry to the Teams site at Institution B.

---

References:

• Microsoft authenticator sending me into a spiral - Microsoft Q&A
• Cannot be added to TEAMS CHANNELS - Microsoft Q&A