Lost access to my Global Admin Account completely (admin.microsoft.com)

Please note that forum moderators do not have access to user account settings and cannot assist with logging in, resetting passwords, or changing access rights. While we do not have access to internal systems or administrative tools required to resolve account-specific or backend-related issues, but we’ll continue doing our best to support you within the scope of our responsibilities.   

Good day @CoskunU and I’m sorry to hear about the difficulties you’re experiencing. 

This issue occurs because the old phone number remains registered as the required second factor for Multi‑Factor Authentication (MFA). As part of its security controls, Microsoft enforces MFA verification before allowing access to an account, and in this case, the verification request continues to be sent to the old number, preventing you from completing the sign-in process. Under these circumstances, restoring access requires an MFA reset.

To move toward a resolution, I suggest the following steps:

1/ Contact other IT admins

Please check to see if there are other IT admins in your organization who can help you with the reset MFA for your account and you can share the steps outlined in the article Manage user authentication methods for Microsoft Entra multifactor authentication. This will help them assist you in resetting your MFA settings and restoring access to your account. 

Once your IT admin has reset your MFA, the next time you log in to your account, you will be guided through the process of setting up the Microsoft Authenticator app again from the beginning by scanning a QR code. This will break the loop and allow you to access your account normally. 

2/ Contact Microsoft Data Protection Support by phone

I understand that you have already attempted to contact Support by phone without success. You may consider contacting Support again using the phone numbers listed in the article below and following the script below to help navigate the automated phone system and reach the appropriate support team more effectively.

Customer service phone numbers - Microsoft Support 

(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.)   

IVR: What kind of problem are you concerned about?   

You: Authenticator.   

A: What products do you use?   

You: Office 365 for business.

Verification: Education or company account?   

You: For companies

IVR: Are you an administrator?    

You: Yes.

IVR: Are there any other administrators in your organization?    

You: No.

IVR: Do you need a... Service request?    

You: Yes. I need to create a ticket. Please send me directly to the Data Protection Team.    

3/ Create a new tenant to submit a support ticket

If you cannot reach a live agent, there is still a workaround, you might consider registering for a new tenant by signing up for a trial subscription and submit your request from there.     

To set up a new tenant, please follow these steps below:

Visit Microsoft 365 Business Plans and Pricing | Microsoft 365. This would allow you to create a new tenant following the prompts provided. Once set up, you can access the admin console of the new tenant and submit a support ticket requesting to speak with the Data Protection team on behalf of your previous tenant.      

Follow the guided setup process to create a new account for a new tenant.  

Once your tenant is created, you should be able to access the support portal and submit your ticket referencing your locked account without further issues

In your ticket description, you'll need to clearly explain that you're trying to regain access to your previous Microsoft 365 tenant and need help from the Data Protection team. Here's a message you can use or adapt:  

"Hello, I’m currently unable to access my previous Microsoft 365 tenant due to losing MFA access.

I created this new tenant solely to request assistance. I kindly ask to be connected with the Data Protection team to verify my identity and help me recover access to the original tenant.  

This is urgent, as I rely on Microsoft 365 for my work and have been unable to operate for several days. I’m available to provide any documentation or verification needed to support the recovery process."  

Ticket Support: In the Microsoft 365 Admin Center > Support > Help & Support. You can raise support ticket at https://admin.microsoft.com/#/support/requests    

Please remember to cancel the trial subscription after your issue is resolved, as this will help you avoid any accidental billing. You may prefer the following resource for detailed instructions: Cancel your Microsoft business subscription in the Microsoft 365 admin center | Microsoft Learn

I hope this helps you regain access to your account quickly. I'm glad to assist and truly hope the information provided has been useful. Please feel free to reach out anytime if you need further assistance.