Your Microsoft account supports multiple aliases, and you can assign one of them to be your primary alias at any time. Making this change has interesting ramifications on how you sign-in to Windows 10 and access services such as OneDrive, Outlook.com, and Outlook.com Premium, among others.

So let’s think about this for a bit.

First, in Microsoft parlance, the email address that you first used to create your Microsoft account—probably at Hotmail or Outlook.com, but possibly at Xbox, Zune, Skype, or elsewhere—is considered your primary alias. It’s the way you sign-in to your Microsoft account and access the services that are associated with that account.

But Microsoft also lets you add other aliases to your Microsoft account. These aliases are alternate ways with which you can sign-in to you Microsoft account. And they can include other email addresses, a phone number, or a Skype name (now deprecated).

Aliases are most useful for email. You can switch between your available aliases when sending email, for example. And many people use aliases to sign up for email newsletters so they can keep on top of spam. But aliases have uses that go beyond email. And by changing your primary alias, you can, in effect, update your online persona with a new identity.

There are, of course, restrictions.

You can create an alias using a Microsoft-type (@hotmail.com, @live.com, @msn.com, or @outlook.com) email address. But that email must not have been already claimed by you or anyone else. This means, sadly, that you cannot use a second Microsoft account you may have an alias for the first. (It also means that you cannot use this method to share information between, or “combine,” two Microsoft accounts. Which would be nice.)

My personal Microsoft account is over 15 years old, and it has an @hotmail.com email address. It’s what I use to sign-in to Windows 10 (when I do sign-in to Windows 10), and it’s the account I use with Office 365 Home, OneDrive.com, Outlook.com (which for me is Outlook.com Premium now), Xbox, and so on.

Though I agree that it’s a bit out-of-date looking, I don’t mind that this account has an @hotmail.com email address back in January, I started testing Outlook.com Premium, which you may recall has some strange alias-related behavior. That is, when you bring your own custom domain to the service, each email account you set up has to be configured as an alias for an existing Microsoft account. Put another way, every user on that new custom domain needs to already have a Microsoft account.

Which is fine. Except that it introduces some weirdness.

Let’s say that my Microsoft account’s primary alias is [email protected] (It’s not.) And then I sign up for Outlook.com Premium using that account, and I configure it to use a custom domain called thurrott-books.com (also not real). So when I create my first Outlook.com Premium user account, [email protected], that account is really just an alias of my [email protected]

This means that they are one and the same. I could sign-in to a Windows 10 PC—or Outlook.com, or Office 365, or my Xbox One, or whatever—with either [email protected] or [email protected] Same result.

Except, that is, for that weirdness I mentioned. When I use the new [email protected] alias to sign-in, I’m really just signing in to [email protected] So when I look at my account settings in Windows 10, I see the Hotmail.com address, not my new custom domain. Likewise, when I sign-in to Outlook.com Premium and click my user account name up in the top right corner, I see my Hotmail.com address … even though I just signed in with [email protected]

That’s because the custom domain isn’t my primary alias. And if I want to always access my account using this new email address, I just need to change my Microsoft account’s primary alias from my old Hotmail.com email address to my new custom domain email address.

You do this on the Microsoft account website: Navigate to Your info > Manage your sign-in email or phone number. After satisfying the two-factor authentication gods, you’ll arrive at the Manage how you sign in to Microsoft page, which includes an Account aliases list. Here, you can change your primary alias at any time. Just click “Make primary” next to the one you want. In my case, the new custom domain email address.

Now, when I sign-in to Windows 10 or whatever using that new address, it stays that way. And I’ve replaced my aging Hotmail address without needing to create a new account. The legacy continues. And more important, all the content and associated services continue too.

Don’t let my usage of Outlook.com Premium and custom domains throw you. You can do this with any Microsoft account, and if you use Outlook.com, OneDrive, and other Microsoft services and wish to do so with a new email address, you can. Just make a new alias, and make it your primary alias.

What’s most interesting about this is that it works. The next time you sign-in to Windows 10, say, it will use the new primary alias, even if you signed in with the old one.

It’s like getting a new start.

Tagged with Microsoft account