How to reset login in Admin business Center, MFa doesnt work, please help!

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 @Erik,

I'm sorry to hear you're having difficulty with MFA when trying to sign in.

Based on your description, it appears that your account is stuck in a Microsoft Authenticator registration loop.

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

If you’re unsure who your administrator is, this article may help: How do I find my Microsoft 365 admin?

If you are the only administrator or no other Global Administrator can access the tenant, the next step is to work directly with Microsoft 365 Business Support. Community forums such as Microsoft Q&A cannot reset, bypass, or remove MFA for administrator accounts. Microsoft Support can guide you through the tenant ownership verification process and help recover administrative access.

Since you have already been trying to reach support by phone, I recommend continuing through the Microsoft 365 Business support channel, as this is the appropriate team for administrator account recovery and MFA-related access issues.

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.

I would also recommend calling during opening hours when possible. From my experience, it can be difficult to reach the right support queue at times, and automated systems don't always behave as expected. If you can't get through on the first try, consider trying again later or at a different time of day.

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.

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.

Warm regards,  

If the answer is helpful, please select "Yes, accept answer". If you have any questions or new updates, please feel free to comment below.