Configuring Microsoft 365 to Use a Custom Domain Name

Image showing several common domain extensions such as .com and .org
A custom domain can add so much to your corporate identity!
Source: EstudioWebDoce on Pixabay

When you set up a new Microsoft 365 account, Microsoft automatically assigns a domain name to your account. This domain name is usually something like <your company> It’s safe to assume that this default domain name will do the job. But it’s still good to go for a custom domain name — because it’ll better reflect your corporate identity.

In this article, I’ll explain how you can acquire a custom domain name and add it to a new or existing Microsoft 365 account. Without further ado, let’s begin!

Acquiring a Custom Domain Name

Hopefully, you already have a custom domain name you can use. But if not, it’s relatively easy and inexpensive to get one. You can go to any one of the countless domain registries available online to purchase a domain name. Any registry you choose will have a search box that allows you to search for a custom domain name. You can see an example of this in the screenshot below.

Screenshot showing the user registering a domain name through a domain registry.
I registered a domain named

After acquiring your custom domain name, it’s time to add it to a Microsoft 365 account. You can do this with a new or existing account. Let’s discuss adding your new domain to a new account first.

Adding Your Domain to a New Microsoft 365 Account

When you set up a brand new Microsoft 365 account, you’ll see a setup wizard when you log into the account for the first time. This wizard walks you through basic tasks such as installing Microsoft Office and adding a custom domain name. As you can see in the screenshot below, adding a custom domain name is as simple as entering the domain name you want to use. 

Screenshot showing the "Does your organization have a domain?" section in the Microsoft 365 setup wizard.
You have the option of creating a custom domain name during the initial Microsoft 365 setup process.

Of course, you don’t have to supply a custom domain name immediately. You can always use your default domain name for now and add your custom one at any point in the future.

Next up comes adding a custom domain to an existing Microsoft 365 account!

Adding Your Domain to an Existing Microsoft 365 Account

So let’s say you weren’t sure what you wanted your domain name to be, and you had to go with the default one. You won’t be stuck with it forever! You can add a custom domain name even after you create the account. To get started, follow these steps:

  1. Log into Microsoft 365 using an account with administrative access
  2. Open the Microsoft 365 Admin Center
  3. Click the Setup tab
  4. Click the Get Your Custom Domain Set Up link (near the bottom of the screen)
  5. Read the warnings about the impact of adding a custom domain on your end users, and click Get Started
Screenshot showing the "Get your custom domain set up" tab in the Microsoft 365 admin center
Microsoft warns you of some potential additional steps involved in adding the domain
  1. Enter your domain name when prompted, and then click Use This Domain

It’s as simple as that. But wait, this is just one part of the process. The next part involves verifying domain ownership, so let’s take a look at that now.

Verifying Domain Ownership

The next step in the process is to verify domain ownership. Essentially, this involves adding a TXT record to the domain’s DNS record. In doing so, Microsoft will assign you a TXT name, value, and TTL that you must add to the domain’s DNS. The steps in this process vary widely depending on where you registered your domain. You can see an example of this process in the screenshot below. 

Screenshot showing the retrieval of a TXT file to add to an existing DNS record on Microsoft 365.
Example of retrieving a TXT file to add it to a public DNS.

Once you add the required DNS record, go back to Microsoft 365 and click the Verify button. Here, Microsoft 365 will check for the existence of the DNS record you created. It’s also worth noting that it can take up to 24 hours for new DNS records to fully go through the system, although the process typically only takes about 10 minutes.

Once the domain verification process completes, you’ll receive a prompt to add more DNS records to the domain’s DNS server. These records aren’t for verification purposes, but you’ll need them to make Microsoft 365 work properly.

Now that we’ve gotten that out of the way, let’s get your company emails set up next.

Changing Your Email Addresses

Once you set up your domain, the last thing you should do is configure your user accounts to use the new domain. To do this, simply follow these steps:

  1. Open the Microsoft 365 Admin Center
  2. Click on Users, followed by Active Users
  3. Select one or more user accounts
  4. Click the More icon
  5. Click Manage Username and Email
  6. Select the domain that you want to use and click Add
  7. Click Save Changes
Screenshot showing the "Active users" tab in the Microsoft 365 admin center
Mapping a mailbox to a new domain name

And that’s it! You’re now a master at adding custom domain names to old and existing Microsoft 365 accounts. More knowledge is always a good thing, right? 

Let’s have a quick recap now.

The Bottom Line

To conclude, having a custom domain name is always a good thing for any organization. Using Microsoft 365’s default domain name just doesn’t feel right. Every organization needs to have its unique corporate identity, and a custom domain name helps with that!

It’s easier to add a custom domain name to Microsoft 365 in the initial account setup process. However, you can still use the default option until you’re ready to add a custom domain later on.

Do you have more questions about adding a custom domain name to Microsoft 365? Check out the FAQ and Resources sections below!


Can I use the default Microsoft domain name indefinitely?

Yes, it’s not mandatory to use a custom domain name. If you prefer to use the default domain name, you can do so for as long as you like.

Can I get around adding extra DNS records to my domain?

In a way, yes. You can enable an option to update the DNS server to point to Microsoft, where Microsoft handles the process. Choosing this option means that Microsoft will be the DNS provider for your domain. This option works, but setting it up can be time-consuming. Furthermore, it’s not the best option if you plan on creating additional DNS records for unrelated services.

What happens if I’m unable to verify my domain name?

Microsoft uses domain name verification to prove that you own the domain name in question. If you cannot verify the domain name, you can’t use it.

Can I add multiple domain names to Microsoft 365?

Yes, you can. Microsoft 365 fully supports having multiple custom domain names. However, you can only map one custom domain name to each mailbox.

What shortcuts can I take when adding the required DNS records for Microsoft 365 to function?

In short, the easiest way to reduce the chances of human error and to save yourself some typing is to copy and paste the DNS record information. It’s also worth noting that DNS records related to Skype and Microsoft Intune are optional. You won’t need to add those records unless you plan on using those services.


TechGenix: Article on Microsoft Azure DNS and Internet Domains

Learn how to use the Microsoft Azure DNS service to delegate a new internet domain.

TechGenix: Article on Removing Domains in Microsoft 365

Discover how you can easily remove domains from Microsoft 365.

TechGenix: Article on Choosing an Active Directory Domain Name

Find out how to choose your Active Directory domain name.

Microsoft: Article on Adding a Domain to Microsoft 365

Educate yourself even further on adding custom domains to Microsoft 365.

Microsoft: Article on Changing Your Email Address to Use Your Custom Domain

Read more on how you can change your email address to have it accommodate your custom domain name.

Microsoft: Guide on Connecting Your Domain to Microsoft Office 365

Check out this guide on how to connect your domain to Office 365.

About The Author

Leave a Comment

Your email address will not be published. Required fields are marked *

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Scroll to Top