Hi @AWANO Kyohei , to change the Azure AD primary domain, follow these steps:
- Sign in to the Azure portal with an account that's a Global Administrator for the organization.
- Select Azure Active Directory.
- Select Custom domain names.
- Select the name of the domain that you want to be the primary domain.
- Select the Make primary command. Confirm your choice when prompted.
Please note that changing the primary domain for your organization won't change the user name for any existing users.
Risks and impacts associated with changing the primary domain may include potential issues with user authentication, application configurations, and email routing. It's essential to thoroughly test and validate the changes after modifying the primary domain.
To validate the changes post primary domain modification, you can:
- Test user authentication with the new primary domain.
- Verify that applications and services are functioning correctly with the updated domain.
- Check email routing to ensure it's working as expected with the new primary domain.
Please let me know if you have any questions and I can help you further.
If this answer helps you please mark "Accept Answer" so other users can reference it.
Thank you,
James