Custom Domain Stuck on "Unverified" in Microsoft Entra ID, Likely Linked to a Different Tenant

Question

We've been trying to add a custom domain to our Microsoft Entra ID tenant for over a week. DNS records are correctly configured and have been in place well beyond the standard propagation window. The domain status still shows as "Unverified."

Based on our research, the most likely cause is that this domain is already registered to a different Entra tenant. We own the domain and can prove it, but we don't have access to the tenant it's currently associated with, and we don't know who does.

We need Microsoft to unlink the domain from that unknown tenant so we can properly verify and use it in ours.

Steps Already Taken:

1. Added the domain in Entra ID under Custom Domain Names.
2. Confirmed the TXT and/or MX DNS verification records are live and resolving correctly (verified via third-party DNS lookup tools).
3. Waited 7+ days. No change in status.
4. Reviewed Microsoft documentation on domain verification. The lingering "Unverified" state matches documented behavior when a domain is tied to another tenant.

What We're Requesting:

We're asking Microsoft Support to confirm whether this domain is registered to another Entra tenant, and if so, to initiate the process to unlink it so we can verify ownership in our tenant. We can provide domain ownership proof (registrar access, DNS control, WHOIS records) as needed.

Answer 1

Hello Tyler O'Donnell,

Greetings! Thanks for raising this question in the Q&A forum.

Your diagnosis is correct. When a domain remains stuck on "Unverified" in Entra ID despite valid DNS records being in place for over a week, the most common cause is that the domain is already registered and verified in a different Microsoft Entra tenant. Microsoft enforces a strict one-tenant-per-domain rule, and the verification process will silently fail rather than surface the specific reason to protect the privacy of the other tenant's existence.

The Q&A forum cannot look up or unlink domains from other tenants — that requires a formal Microsoft Support case. Here is the correct process to resolve this.

1. Confirm the domain is genuinely claimed elsewhere before engaging support. You can check whether a domain is associated with a Microsoft tenant by querying the OpenID Connect discovery endpoint. Replace yourdomain.com with your actual domain in a browser:

https://login.microsoftonline.com/yourdomain.com/.well-known/openid-configuration

If this returns a valid JSON response with a token_endpoint value pointing to a tenant ID, the domain is actively claimed. If it returns a 400 error, the domain may be in an unverified or abandoned state in that other tenant, which is a slightly easier resolution path.

1. Open a Microsoft Support ticket — this is the only path to resolution. In your Azure portal, navigate to Help + support > New support request and set the Issue type to Technical, with the service as Microsoft Entra ID and the problem type as Domain Management. Describe that your custom domain is stuck Unverified and that you believe it is claimed by another tenant you do not have access to.
2. Prepare domain ownership evidence for the support case. Microsoft Support will require proof that you legitimately own the domain before they take any action. Gather the following:
   • Registrar account access screenshots showing your organisation as the registrant
   • WHOIS records showing your organisation name and contact details as the registered owner
   • The ability to create arbitrary DNS records on the domain (which you have already demonstrated by publishing the TXT verification record)
   • Any business documentation linking your organisation to the domain
3. Understand what Microsoft Support can do. If the domain is found to be verified in another tenant that has an active subscription and an administrator, Microsoft cannot forcibly remove it — they will need to contact that tenant's admin. If the domain is in an abandoned tenant (no active subscription, no active users, or added but never verified), Microsoft Support can expedite removal and allow you to verify it in your tenant. DNS control is the strongest proof of ownership you can present, as it demonstrates you control the domain at the registrar level.
4. If you believe the other tenant is a former Microsoft partner, CSP, or trial account tied to your domain, mention that explicitly. Domains are sometimes claimed during trial sign-ups or by CSP partners who set up Microsoft 365 on behalf of customers and registered the domain in their own tenant. Providing this context to Microsoft Support helps them identify and resolve the situation faster.
5. As an interim workaround, consider using a subdomain. If you need to proceed with Microsoft 365 or Azure deployments while the domain dispute is being resolved, you can add and verify a subdomain of your domain (for example mail.yourdomain.com or m365.yourdomain.com) in your tenant. Subdomain verification in a different tenant is permitted even when the parent domain is claimed elsewhere, as Microsoft Entra allows cross-tenant subdomain verification. This lets you set up users and services in the interim.

If this answer helps you kindly accept the answer which will help others who have similar questions.

Best Regards,

Jerald Felix.