Hi @Nattapong Rojnakarint,
Good day, and I appreciate the clear description of your issue.
As part of the community support team, my access is limited and I cannot make changes to administrator-level settings. For security reasons, the options to recover access may vary depending on whether another administrator is available in the organization.
With that in mind, below are the available options can try to resolve the issue:
Option 1: Contact other IT admins
You may want to check if there are any other IT administrators in your company who still have access and contact them. They would be able to assign the Global Administrator role to another user in your organization.
For reference: Assign admin roles in the Microsoft 365 admin center - Microsoft 365 admin | Microsoft Learn.
Option 2: Create a new tenant to submit a support ticket (Alternative method)
If the original admin was the only administrator for your organization, the Microsoft Data Protection Team has tools and processes in place to verify identity and regain access to administrator accounts. The team can only be reached via opening a support ticket.
As contacting support by phone to create a ticket has been difficult, there is still a possible workaround. You may consider registering a trial tenant by signing up for a trial subscription using the link: Microsoft 365 Business Plans and Pricing | Microsoft 365. (please select "Try for free" under a business subscription and click Next).
When prompted, enter your email. You can use your personal email or create a new Microsoft personal account for this step.

Then select Set up account to move forward.

From this step, the system should guide you through creating your tenant and assign you a default onmicrosoft.com domain.
Once set up, you can access the admin console of the trial tenant using the onmicrosoft account and submit a support ticket requesting to speak with the Data Protection team on behalf of your previous tenant.
To create a support ticket: In the Microsoft 365 admin center > Help & Support.
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 unable to access my previous Microsoft 365 tenant because the only admin is no longer available.
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."
It is important to note:
- Please remember to cancel turn off recurring billing for the trial subscription once your issue is resolved to avoid any unintended charges. You may prefer the following resource for detailed instructions: Cancel your Microsoft business subscription in the Microsoft 365 admin center | Microsoft Learn.
- During the initial setup of the trial tenant, please ensure MFA is configured and not skipped, as skipping this step may result in access issues or restricted recovery options later.
You’ll need to verify your ownership of the Microsoft 365 tenant with Microsoft’s Data Protection Team. This verification process typically requires providing the following documentation:
- Proof of domain ownership, such as access to manage DNS records
- Billing or subscription information, including payment methods or account history
- The Tenant ID of the affected Microsoft 365 organization
- Official business registration documents
- Documentation confirming you are an authorized signatory for the business
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, we’ll continue doing our best to support you within the scope of our responsibilities.
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.
If you find my post useful, kindly consider upvoting it. Doing so can assist others in the community who may have similar questions in finding solutions more quickly.
Thank you for your kindness and contributions to the forum.
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