How to Change Your Default onmicrosoft.com Domain for your Microsoft Tenant

The "onmicrosoft.com" domain is a default domain provided by Microsoft for users of their cloud-based services, particularly Microsoft 365 (formerly known as Office 365). When you sign up for Microsoft 365 or Microsoft Entra ID (formerly Azure AD), Microsoft automatically assigns a unique domain in the format "yourorganization.onmicrosoft.com" to your account.

At times, Microsoft assigns a domain that may not align with our preferences. Previously, there was no option to change it; the only workaround was employing a custom domain.

Fortunately, Microsoft has introduced a solution to address this issue by allowing up to 5 onmicrosoft.com domains to be associated with your tenant. This alleviates the challenge posed by the initial assignment, which was previously unchangeable. I'd like to guide you through the process of adding and changing the default onmicrosoft.com domain for your tenant.

• Begin by accessing your Microsoft Entra ID portal at https://entra.microsoft.com/
• Navigate to the "Settings" menu and select "Domain names."

• Here, you can manage all the domains linked to your tenant. To add a custom domain, proceed as follows:

• Within this section, you'll find the option to add your new onmicrosoft.com domain name.

• Now, you can designate this new domain as your initial domain.

?And there you have it! Your onmicrosoft.com domain is now different from the initial one. If you don't have another primary domain, such as a custom domain, you also have the option to make this new domain the primary domain for your tenant.

In short, Microsoft now lets you have up to 5 onmicrosoft.com domains for your tenant, offering a solution to unwanted domain assignments. The steps shared above walk you through adding and changing your default onmicrosoft.com domain hassle-free. Make the most of this flexibility to customize your Microsoft environment as you like.