Can't sign back into business admin account, authenticator issue

Hello HB,

Since you are the only admin and cannot use your Authenticator app, your only option is to contact Microsoft Support directly to initiate an "Administrator Account Recovery" process.

Here are the specific steps you must take:

Use the Right Support Channel: Visit the official Microsoft Support contact page. When navigating the options, select "Microsoft 365" as the product and "User and domain management" or "Account and billing" as the category. The goal is to reach the commercial support team, not consumer support.

Prepare for the Call: You will need to prove you are the account owner. Have the following information ready:

• Your Microsoft 365 tenant domain name (e.g., yourcompany.onmicrosoft.com).
• The billing address and details associated with the subscription.
• Any Invoice numbers or Order IDs you may have received via email.

The support agent will guide you through a verification process. Once your identity is confirmed, they have the tools to reset the multi-factor authentication (MFA) requirements on your account, allowing you to set it up again with your new phone.

This is the only supported path to resolve this issue. I strongly recommend you initiate this process immediately.

Please hit "Accept Answer" if you find my response helpful to you, appreciate it~

Hello @HB

Has your issue been solved? If it has, please accept the answer so that others know this is a quality answer and can help similar issue. If not, is there anything I can help you with? Please let me know.