I got a new phone and my Authenticator app won’t pop up when trying to log into an app

Question

I got a replacement phone. I can not login to the old phone. Authenticator will not work on my new phone to pop up when trying to authenticate

Answer 1

Hi @Brandonne Primous

Thank you for reaching out to Microsoft Q&A Forum.  

I think MFA of old mobile phone is existing so that authenticator will not work on your new phone to pop up when trying to authenticate. You have to delete MFA on old device. To solve this problem, you should few steps below (assuming that you can sign-into your account using old phone's Authenticator):  

1. Go to the https://mysignins.microsoft.com/security-info  

       2.  Select Security info you’ll see list of sign-in methods  

       3.   Click Delete on row which have your model of mobile phone  

       4.   Click OK and try login on your new mobile phone.  

Assume if you had a lot of emails, which are from work or school, its security settings, including MFA, are managed by IT department. As general Microsoft Support, we don't have the administrative access to directly change these settings.    

To quickly resolve this and regain access if you don't have access to your old phone's Authenticator, the most effective step is to contact IT Support or Help Desk directly. Only they have the ability to adjust your MFA settings, reset them, or help you set up a new verification method.   

When you contact them, providing these details will be very helpful:   

• Your full name and current email address.   
• The exact error message you're seeing: "enter the code displayed in the authenticator app on your mobile device."   
• Explain that you're locked out because you don't have an authenticator app set up for this account, and no alternative options are shown on the login screen.   
• Mention you've tried logging in from multiple devices (computers, phones) with the same result, confirming it's an account-level issue.   

Once IT team helps you regain access, you can manage your security verification methods (like adding a phone number or setting up the Authenticator app again) by visiting your security info page. This allows you to control which methods you use for MFA in the future.  

You can also ask for your Global Administrator and send them follow link Manage authentication methods for Microsoft Entra multifactor authentication so that you can Re-register MFA 

If you need further assistance, feel free to ask!   

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