one of our client domain is showing verified in a M365 account. but they don't know the tenant even admin credentials. We need urgent support, kindly help

Question

One of our client want to migrate email from gsuit to office 365 but when we trying to verify the domain in M365 temnant , that is giving error that this domain is alredy verified in a M365 tenant. Client don't know that where it is verified also we checked all user name like admin,it , administartor with that exixting tenant but unable to find.

Answer 1

Dear @Nishant Tyagi,

Thank you for posting your question in the Microsoft Q&A forum.

Based on your description, the issue occurs because your custom domain might be already verified in another Microsoft 365 (Entra ID) tenant. A domain can only be associated with one tenant at a time, and Microsoft does not allow it to be verified again until it is released from the existing tenant.

Since you do not know the tenant's name or any global admin credentials, this cannot be resolved from the admin portal or through self‑service troubleshooting. In this situation, the only supported resolution is to contact Microsoft Support and request assistance from the Data Protection / Tenant Recovery team.

Therefore, I recommend you create a support ticket in the Microsoft 365 admin center. Be prepared to provide proof of domain ownership (such as DNS or registrar access), along with your business contact details, as Microsoft will require this to proceed. For reference:  Get support | Microsoft Docs   

If your client cannot access to your Microsoft 365 Admin Center, I recommend creating a new, temporary Microsoft 365 account to contact the support team online. 

• Sign up for a new Microsoft 365 Business trial using this link: Compare All Microsoft 365 Plans. You will need to use a different, personal email address to register. 
• Once the trial account is created, log in to its Admin Center. 
• From the Admin Center, open a new Service Request. For reference:  Get support | Microsoft Docs   
• In the ticket description, explain that you need to speak with the Data Protection team on behalf of the primary tenant (your.onmicrosoft.com). Provide your locked account's details and a good contact number for them to reach you. 

Important: Please remember to cancel the trial subscription after your original account issue is resolved to avoid any future charges. 

Note: Please understand that as a forum moderator, my role is to provide general guidance and troubleshooting support. I don’t have access to internal systems or backend tools, and I appreciate your understanding of these limits.

I hope the information shared helps point you in the right direction. Please try the steps above and let me know if they work. If not, we can continue working together to narrow this down.

The first response may not always resolve the issue right away, but with your help and more details, we can work toward a solution.

Thank you for your patience and understanding. I'm looking forward for your reply.

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