Loss of MS Authenticator of Global admin account just only one

Please note that this forum is a community support space, so I don’t have the ability to access tenant data or perform actions such as resetting MFA/security information directly. I can only guide you based on documented processes and experience, but I will do my best to point you in the right direction so this can be resolved properly.

Dear @Dopod,

I'm sorry to hear that you've already tried multiple support channels, including phone, web forms, and email, without being able to reach the appropriate support team.

Based on your description, this appears to be an administrator MFA lockout scenario caused by the loss of the device that contained Microsoft Authenticator.

If your organization has another Microsoft 365 or Entra ID administrator, I recommend contacting them first. They can review your account's authentication methods and, if necessary, reset your MFA registration, remove any old Authenticator registrations, or provide an alternative sign-in method so that you can register Microsoft Authenticator on your current device.

Your administrator can follow the guidance in the following article: Manage authentication methods for Microsoft Entra multi-factor authentication

Therefore, if you are the sole Global Administrator on the tenant and don’t have access to any other MFA methods, then this becomes a full admin lockout situation. In that case, the only supported way forward is to contact Microsoft Support and request a tenant admin recovery / MFA reset. This request is handled by the Microsoft Data Protection / Identity team, who can verify ownership and unblock or reset the MFA configuration for your account.

I understand you've already attempted to contact support by phone. However, in my experience, reaching the correct support queue does not always work as expected on the first attempt. If possible, I would recommend trying again during local business hours.

Please try to find the related hotline number to call the frontline let them raise a ticket for you: Customer service phone numbers - Microsoft Support 

If you choose to contact Microsoft Business Support by phone, you may first be connected to an automated system before contacting a support professional. Based on similar cases of administrator lockouts, the conversation can go something like this:

Automated system: Are you calling as a private individual or a business customer?

You: Business customer.

Automated system: What do you need help with today?

You: Authentication problem.

Automated system: Which Microsoft product or service is affected?

You: Microsoft 365 for business.

Automated system: Can't sign in to the Microsoft 365 Admin Center?

You: Yes.

Automated system: Do you have another administrator in your organization?

You: No, I'm the only administrator.

Automated system: Are you a global administrator for the affected tenant?

You: Yes.

Automated system: Are you calling about an existing support case, or would you like to create a new one? You: I need to create a new support case.

In many cases, the automated system will then indicate that it can connect you with a support representative who can help create a support request and forward the case to the appropriate recovery team.

If your organization’s Office 365 Business subscription was purchased through a partner or reseller, and you’re unable to open a service request directly, you may also contact the reseller’s support provider and ask them to open a support request on your behalf.

Alternatively, you can try set up a new trial tenant and submit your support request, please follow this link to create a trial tenant: Compare Office 365 Enterprise Pricing and Plans | Microsoft 365 - after that you will be able to access to Microsoft 365 Admin Center to raise the ticket

Assuming that you have already created an account after registering a free trial and you can go to Microsoft 365 admin center and click Support > Help & support icon to raise your ticket. The agent will be able to create a ticket for you under the affected tenant and then transfer this ticket to Data Protection team who could help you to regain access.

Please mention that you are raising ticket on behalf of the affected tenant that you do not have access to. The support team will help you to create ticket on the affected tenant then later on the Microsoft Data Protection team will assist you.

Note: This process will take more time than usual (7-14 working days) for your account to get access again as Data Protection is always overwhelmed with the number of tickets. As I am forum moderator, I do not have access to Microsoft internal system to assist or push this process to be quicker.

If you do create the trial and it resolves the issue, please remember to cancel the subscription afterward to avoid any related charges. This new trial tenant will not give you access to any of the data or settings in your original locked tenant. It is solely a temporary means to contact Microsoft support.   

I hope my information is helpful. Please give me any updates once you get this resolved.

Warm regards, 

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

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.