It’s not letting me use authentication on my new phone I have to use my old ome

Hi @Brown, Shae,

Thank you for posting your question in the Microsoft Q&A forum, and I’m sorry to hear you're having trouble accessing your account due to Microsoft Authenticator app.

This issue commonly occurs when your Multi-Factor Authentication (MFA) settings need to be reset, particularly after changing devices or reinstalling the Microsoft Authenticator app. 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 on your new phone.

To help determine the best solution for your situation, could you confirm the following details:

• Are you trying to sign in using a personal account (e.g., @hotmail.com) or a work or school account (@yourcompany.com or @ yourschool.com)?

If you are using a work or school email address, the MFA settings are managed by your school IT department. For assistance with resetting or updating your MFA, you will need to contact them directly to resolve this. 

Please contact your school's IT Help Desk or support team and explain the situation. You can say: "I am stuck in a login loop between Outlook and the Microsoft Authenticator app. I cannot get the code to sign in." 

Specifically ask them to “Reset my MFA settings or allow me to re-register for MFA". This is a standard request, and your school's IT team should be able to assist you with it.

You can also share the steps in this Microsoft article for them so they can help reset your MFA settings for you Manage user authentication methods for Microsoft Entra multifactor authentication.

In case you are using a personal account, kindly share your account type so I can provide the correct instructions or connect you with the right team.

Once your school's IT admin has reset your MFA, the next time you log in to your account, you will be guided through the process of setting up the Microsoft Authenticator app again from the beginning by scanning a QR code with your new phone. This will break the loop and allow you to access your account normally. 

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 helps you regain access to your account quickly. I'm glad to assist and truly hope the information provided has been useful. Please feel free to reach out anytime if you need further assistance.

If you find my post helpful, kindly consider marking it as the accepted answer. Doing so can assist others in the community who may have similar questions in finding solutions more quickly.

Thank you for your kindness and contributions to the forum.

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

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To use authentication on your new phone, you need to set up Multi-Factor Authentication (MFA) on that device. If your old phone is still receiving the authentication requests, you will need to register your new phone for MFA. Here are the steps you can follow:

1. Use Your Old Phone: If you still have access to your old phone, use it to complete the authentication process while setting up your new phone.
2. Register New Device: You may need to go through the MFA setup process again on your new phone. This typically involves signing into your account and selecting the option to set up MFA.
3. Contact Admin: If you are unable to set up MFA on your new phone, ask your IT administrator to reset your MFA settings. They can do this by following the appropriate steps in the admin portal.
4. Use SMS/Call for MFA: If you are using SMS or call-based MFA, ensure that your new phone number is active and can receive messages or calls for verification.

Make sure not to factory reset your old device or remove the Microsoft Authenticator app until you have successfully set up your new device for MFA.