I cannot log in to my admin account

Good day Carlos, 

I understand that you cannot sign in to your administrator account and need to remove your email domain from the current Microsoft 365 tenant. If you also need to delete the tenant, please refer to the following documentation after you have regained access to your administrator account: Delete a Microsoft Entra tenant - Microsoft Entra ID | Microsoft Learn 

The appropriate solution depends on whether another administrator is available and what prevents you from signing in. Please follow the option that matches your situation: 

Option 1: Reset the administrator password 

If you have forgotten the password or the password is no longer accepted, try the Microsoft password reset page. 

Go to the https://passwordreset.microsoftonline.com/. 

Enter your administrator email address and complete the verification steps. 

Create a new password, then try signing in to the Microsoft 365 admin center. 

This option works only if self-service password reset was previously enabled and you can access one of the registered verification methods. 

Option 2: Ask another administrator to restore your access 

If another administrator is available in your organization, ask them to reset your password or your Multi-Factor Authentication (MFA) methods through the Microsoft Entra admin center. This is usually the quickest way to regain access. 

For reference: Manage authentication methods for Microsoft Entra multifactor authentication - Microsoft Entra ID | … 

Option 3: Contact Microsoft Support 

If you're the only administrator and you've been locked out of the account, you'll need to contact Microsoft's Data Protection team for assistance. They are the only team authorized to help recover access in situations involving the sole administrator account. 

You can find Microsoft's support numbers here: Contact Microsoft customer support | Microsoft Support 

When contacting Microsoft, be prepared to verify your subscription ownership by providing details such as your organization name, billing or payment information, registered phone number and alternate email address. 

Once your identity is verified, the team can help restore access to your administrator account so you can update your password or MFA settings and proceed with the domain or tenant removal. 

Tips for navigating the IVR:  

(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 problem is bothering you? 

Client: Lost access to the only admin account. 

IVR: What product do you use? 

Customer: Office 365 for business. 

IVR: School or Business account? 

Client: Business account. 

IVR: Are you an administrator? 

Client: Yes. 

IVR: Is there another administrator in your organization? 

Client: No. I am the only admin in my tenant.     

IVR: Do you need to create a support ticket? 

Client: Yes. I need to create a ticket. Please send me direct to the Data Protection Teams. 

In case you are unable to contact the frontline support: 

Consider signing up for a trial subscription to create a new tenant. Visit Microsoft 365 Business Plans and Pricing | Microsoft 365. 

Once the new tenant is set up, you can access its admin center and submit a support ticket through Microsoft 365 admin center > Support > Help & Support to contact the Data Protection team regarding the previous tenant. 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 

If your organization's subscription is from a partner or reseller: Contact the reseller's support provider to help open a service request on behalf of you instead. 

Additionally, here are some reference threads where I have helped other admins contact Microsoft Support, which may give you confidence in using these options: 

Note: These threads involve sole administrators who lost access to their accounts due to MFA-related issues. While the specific circumstances may differ, the process for contacting Microsoft Support is the same. 

Global Admin locked out after iPhone replacement - Authenticator MFA cannot be re-registered 

Sole Global Administrator locked out 

I wish I could help more directly, but as a fellow user in this community, providing these steps is the best support I can offer. I hope this helps point you in the right direction. If you have any updates or additional questions, feel free to reply back and I'll do my best to assist further. 

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