Office 365 – Be mindful of the “Domains” that you enter in your tenancy

This is just a quick little post to remind you to be “mindful” of the domains you configure in your Office 365 tenancy, specially so when you are at the first steps of setting up a new tenancy.

People who don’t deal with this stuff on a day-in, day-out basis can get confused about all the information that Microsoft asks for in the process of setting up a tenancy.  It’s not all that complicated but the following is a refresher on what is required.

The first thing that is required to set up a tenancy is Microsoft will ask you what you want as your “” domain.  What you choose, here, will become your permanent, basic domain identity in Office 365.  Every tenancy in Office 365 has an identity and, by extension, every user in your Office 365 tenancy will have an identity based on that same domain.  It makes sense to put some thought into your desired identity; picking “” , for example, may not be the best choice going forward.  User’s may not like having the identity [email protected]”.  So give some thought to what you pick for this as it will be with you for long, long time.

The domain won’t be the domain name you present to the outside world, that will be your already existing domain such as (assuming that you aren’t starting from absolute scratch).  As an example, my personal domain is “” so I want my Office 365 tenancy to use that as the primary domain and identity.  When I set up my tenancy and Office 365 asked for my domain, I gave it and then Office 365 gave me steps to follow to verify ownership of

This is all fine but this is also where I have seen people go off the rails.  I might have a website (or websites) that are part of my domain so I could have or or any number of other variations but these are not domains!  The domain is just the part.  There are DNS records within my domain that point to the various sites and services that support my domain but there is still only a single domain.  The problem I have seen is that some people try to set up as another domain and then get totally messed up!

I had this happen the other day with a client and they had unknowingly flipped their primary login identity to being [email protected] and then thought they were locked out of Office 365.  As my contact was the only user created inside the tenancy we had no way of logging in to the tenancy to fix her account.  I got Office 365 support involved and they were able to determine that the tenancy was ok and they identified the login for the user as [email protected].  I logged in as the user, now that we knew what the login was, created a net-new user with Global Admin rights, logged in as the new user and fixed my contact’s account.  Keep in mind that you cannot edit your own account in Office 365, hence the need to create the other admin user in order to fix the original admin user.

Keep all of this in mind and your tenancy set up and domain configuration will be as easy as possible.