AADSTS5000228: Access to tenant is denied - sole Global Administrator locked out of newly created tenant

Please note that this is a community forum where users help one another. I do not have control over user accounts, including login issues, password resets, or access changes.

Dear Kazuki Sasaki,

Good day! Welcome to Microsoft Q&A forum!

I’m sorry to hear you're having trouble accessing your Global Admin account. I understand how concerning and it can be to lose access to your Microsoft 365 tenant, especially newly created tenant.

Because administrator accounts have elevated permissions, Microsoft Entra ID requires them to use multi‑factor authentication (MFA) to maintain a higher level of security. In new tenants, MFA for administrators is enforced automatically through Security Defaults. This protection is enabled by Microsoft by design to reduce the risk of account compromise and is now a standard requirement for administrative access.

If MFA registration is interrupted during initial tenant setup, the administrator account can become temporarily inaccessible. This may result in errors such as AADSTS5000228 – “Access to tenant is denied”, preventing sign‑in to the Microsoft Entra admin center and Microsoft 365 admin center. In this state, self‑service recovery options are not available.

With that in mind, please follow the steps below to complete the account recovery process and regain access.

1/ Contact Microsoft Data Protection Support by phone

Because you're the only admin, in this situation, the Microsoft Data Protection Team has tools and processes in place to verify identity and regain access to administrator accounts. You can try reaching out to Microsoft global customer Service phone to raise a request for resetting your authentication method here: Contact Microsoft customer support(for Work account, scroll down to find your region's number).

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 

(Important Note to reach a live support agent: Sometimes, you would hear the computer-generated voice at first, please kindly wait for it to end, and if an agent is available, you would be directed to them and get your 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.)

2/ Submit a support request via another tenant.

First, do you happen to know anyone with an active Microsoft 365 Business subscription who may be willing to contact Microsoft Support on your behalf? While they would not be able to authorize changes to your tenant, they may be able to help open a support request and obtain guidance on the appropriate recovery process.

Besides, you can create a trial tenant account and submit your request from there.    

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

• Visit Compare Office 365 Enterprise Pricing and Plans | Microsoft 365, choose any plan and click try for free to start a free trial.    
• 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 the ticket's description, you could refer to this message "Hello,

I am currently locked out of my Microsoft 365 tenant because multi-factor authentication is enforced, and I am unable to complete the verification process. I am the only global administrator for this tenant, which means I cannot access my account or the Microsoft 365 Admin Center.

To resolve this, I have created a new tenant and would like to be connected with the Data Protection Team to verify my identity and assist with regaining access. I am available to provide any required documentation or verification to support the recovery process."

Ticket Support: Log in the Microsoft 365 Admin Center using the newly created trial admin account (not the currently locked one) > Support > Help & Support. You can raise support ticket at: https://admin.microsoft.com/#/support/requests   

When you open a support ticket, please make sure to turn off the Support Assistant (AI) in the help panel.  

Several customers have reported issues when the Support Assistant is turned on the system sometimes fails to display the “Contact Support” option.  

As shown in the screenshot, simply switch Support Assistant > Off, then type your issue description. Once the AI is off, the “Contact Support” button will appear normally, allowing you to submit a ticket directly.

• After clicking on "Help & Support" button, you can type "I need agent support via phone or email". After that, you can click on "Contact support" 
• Choose contact method: "Phone" 
• Fill all the information in this contact support details, please describe your situation carefully so they will have enough information to help you. 
• Finally, click on "Contact me"
• After completing them, you will receive an email appointment for a meeting to review this issue professionally together. 
• For more details, you could refer to this article: Get support for Microsoft 365 for business 
• 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.   
• Be prepared for Microsoft support to ask for verification of your identity and administrative rights for the locked tenant.   
• The resolution time might be longer as you are contacting support from a different tenant.   
• Remember to cancel the trial subscription for the new tenant once your issue with the original account is resolved to avoid any unintended charges. You can typically do this within the Microsoft 365 Admin Center under "Billing" > "Your products."

Kindly let me know when there are updates or if you need further assistance. Any updates you’re able to share would be really helpful.

I'm here and happy to help! Thank you for your kindness and patience!