Hi @Parkson ,
Thank you for reaching out on the Microsoft Q&A forum. We understand that you’ve lost your mobile device and no longer have access to the Authenticator app. We’re happy to help guide you through the recovery process.
According to this issue, may I know if you know any other Global Administrators in your organization?
- If yes, please ask them to follow this article to proceed to reset your 2FA so that you could re-register again: Manage authentication methods for Microsoft Entra multifactor authentication - Microsoft Entra ID | Microsoft Learn
- If no, then you are the only Global Administrator and you are completely locked out from the tenant. You might need to contact us via phone service number: Customer service phone numbers - Microsoft Support. The agent will be able to create a ticket for you under the affected tenant and then transfer this ticket to DataProtection team who could help you to regain access.
Please note that this team is always overwhelmed, so you might need to wait for them to call you, this should take 3-10 working days. I know that this is not a convenient solution to hear but it seems to be the only way, and it's recommended that you should have a secondary/backup Global Administrator to fix this issue on your own.
If you need further assistance, please let us know.
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