Recover access to a Microsoft 365 business account

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 @Cristina Catargiu,

I hope you’re having a good day.

From your description, I understand that your organization's Microsoft 365 Business Standard tenant is currently in a difficult situation because the administrator can no longer sign in. The administrator is being prompted for MFA verification but no longer has access to the previously configured Microsoft Authenticator device after changing phones.

First, if there is another Global Administrator or Privileged Administrator in the tenant, that person may be able to help reset MFA methods, update authentication information, or restore access to the affected administrator account.

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

However, if the affected administrator is the only administrator remaining in the tenant, and there is no other account with sufficient administrative permissions, 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.

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 

(Depending on your country or region, when you call the support number, you may hear an introduction of about 30 seconds such as "you can visit the link...". You can ignore this introduction and wait until you are presented with the options. Then press "1" as a business email user, and again "1" for technical help.)     

In some countries, this is an automated conversation: First, when you call the hotline, they will ask you what kind of problem you are struggling with.    

Answer: Authenticator.    

A: What products do you use?    

B: Office 365 for business.    

Verification: Education or company account?    

B: For companies    

A: Are you an administrator?    

B: Yes.    

A: Are there any other administrators in your organization?    

B: No.    

A: I need one.... Service request?    

B: Yes    

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, 

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