How to add custom domain to Azure Active Directory?

Question

I created a Free Trial Azure subscription.

Then due to country/region issues I had to add another subscription and migrate my data using Azure support. In the new subscription's AD, I had configured and added my Custom Domain by verifying with TXT record.

Before the migration process I had created a website with Azure AD authentication in the old subscription.

After the migration, I have not tested the website, but the directories seem to have somehow merged, and my previously verified custom domain is not showing up in the AD and I am unable to re-verify it due to the "Could not verify this domain because it was previously configured for your tenant or for another tenant." error. My new subscription's portal url itself is only https://manage.windowsazure.com/@customdomain , this change happened immediately after I verified my custom domain previously.

I need it in my AD so I can add organizational users to my AD - currently it has only users with Microsoft Accounts.

How to go about this?

PS: My old "Free Trial" subscription has been disabled but it unfortunately is not even getting removed. I have pleaded with Azure support to cancel that old subscription but they are saying it is already in cancelled state. I am unable to access this page https://account.windowsazure.com/Subscriptions to remove it myself, I keep getting a "We are sorry, but we could not complete that operation." message with the URL set to https://account.windowsazure.com/Error/403/100

And no, I did not have any AD account with Office365, lots of posts on MSDN forums seem to cover this scenario.

Answer 1

Azure Active Directories can never merge.

But this error can be fixed: "Could not verify this domain because it was previously configured for your tenant or for another tenant"

We need to access the old tenant (something.onmicrosoft.com) via Office 365 Admin center/Azure AD PowerShell/Azure Portal where this domain was added either and get that domain removed either through Portal/PowerShell. After this, you will be able to verify that domain to your tenant.