Dear @Kniest, Roos
Thank you for posting your question in the Microsoft Q&A forum. Based on your inquiry, we understand that you have required an instruction to reset your password and reset your authenticator app also cannot access because of device changing. In my perspective, I suggest you following these steps to recovery your account:
If you use your personal account:
You can fill the form in this Help with the Microsoft account recovery form - Microsoft Support or you can contact direct with Microsoft Support Customer service phone numbers - Microsoft Support
If you use your organization account and you know your admin in your organization:
You can request to your admin to follow these steps:
- Sign in Entra ID
- User -> All Users -> Your Account
- Revoke Sessions (requiring the user to re-sign in from all devices) -> Reset password.
You can also ask your administrator to reset your MFA to help secure your account. Please share this article with them and request that they follow the steps to reset your 2FA, so you can re-register it on your devices
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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