Hi @Rob
Thank you for Reaching Out Microsoft Q&A Platform.
Based on your query, I understand that you would like to configure custom domain and use it is a default domain while creating users.
Before proceeding with verification of domain in Azure, could you please make sure your domain has a DNS host. Add the required DNS records to any of the third-party domain hosts. Once you have the domain with DNS, you will add the domain as custom domain in Azure. Now collect the TXT records from Azure and those to your domain at host which helps in verifying the domain in Azure. Once it is verified, you can make it as Primary domain. When creating new Azure users with your custom domain (@xeres.co.uk), you will be able to see the custom domain as suffix.
To do this, follow these steps:
- Go to the Azure portal (portal.azure.com).
- Navigate to Custom Domain Names.
- Ensure that
xeres.co.uk
is verified and set as your primary domain.
Once you have completed the verification process and set your custom domain as the primary domain, any new users you create will have their UPN default to your custom domain (@xeres.co.uk) instead of the onmicrosoft.com domain.
For additional Information Refer this Documents: https://learn.microsoft.com/en-us/microsoft-365/admin/setup/add-domain?view=o365-worldwide#add-a-domain
https://learn.microsoft.com/en-us/entra/fundamentals/add-custom-domain
Hope this helps. Do let us know if you any further queries.