If you’ve created a lot of Microsoft 365 tenants as I have, you’ve likely run into this scenario before. You are attempting to create the tenant using a domain that you own but find that the tenant has already been registered during the Microsoft 365 tenant creation. This is possible because domain ownership is not verified during the tenant creation, as you are actually creating a tenant that initially only has a .onmicrosoft.com domain (ex: yourdomain.onmicrosoft.com). Only after the initial creation are you able to add a TXT record to your DNS registrar in order to confirm domain ownership.
This could have happened because someone else legitimately registered a tenant using your domain, as odd as that may be if they did not actually own the domain. In this case, you may be able to open a Microsoft ticket to find out more information about who registered it and see if you are able to negotiate taking it over. A more likely situation is that a former IT staff member did a self-service sign-up for a cloud service during an initial review of Microsoft 365. It could even be that a current staff member did it but did so long ago that they don’t remember doing so. This is the situation that applies to steps that follow, which outlines performing an admin takeover on an unmanaged tenant.
Before proceeding, it is assumed that your tenant was created using self-service sign up, self-service is still enabled in your tenant, and the tenant is unmanaged. Taking over the tenant will not impact any existing information or services.
You should have access to the admin center for the tenant using the account you initially created in step 2! Luckily Microsoft has this process available, as I’ve seen several situations arise where a client was unaware they had an existing tenant and would prefer not to have to use an alternative for their .onmicrosoft.com. The main reason for using this domain is that it will be used in conjunction with SharePoint (ex: yourdomain.sharepoint.com). Otherwise, the .onmicrosoft.com domain is not typically public facing.
Now that you have access to your Microsoft 365 tenant don’t hesitate to reach out to the experts at Sikich for assistance with configuring any of the many cloud services available from Microsoft!
This publication contains general information only and Sikich is not, by means of this publication, rendering accounting, business, financial, investment, legal, tax, or any other professional advice or services. This publication is not a substitute for such professional advice or services, nor should you use it as a basis for any decision, action or omission that may affect you or your business. Before making any decision, taking any action or omitting an action that may affect you or your business, you should consult a qualified professional advisor. In addition, this publication may contain certain content generated by an artificial intelligence (AI) language model. You acknowledge that Sikich shall not be responsible for any loss sustained by you or any person who relies on this publication.