Creating a subdomain in O365

New Contributor


Is there any way of creating a subdomain in O365 with an already existing domain?

Example: where is the main domain controlled by the NS pointers by Microsoft.

It seems that the only way is to move the domain outside O365 to a more advanced DNS server.

All threads that I checked says that you have to move the domain to an external DNS, but they are a bit old.

The DNS editor in admin center is very simple.  No other way of doing this?



Best Regards



3 Replies

Hi @headmaster,


Is advised to use a DNS managed externally to have other options that are not available on DNS managed by Office 365, you can read more here


Best Regards,


Nuno Árias Silva 

@Nuno Silva 


Thanks for answer.


But to change a domain to an external DNS provider is always a risky business with a risk for down-periods for both homepage, mail, SharePoint and Teams. I would not say that it is an easy thing to fix for a medium size company with important communication flow.




Hi @headmaster,


If you prepare all DNS records on the destination DNS when you change the name servers on your registrar of your domain, you will not have any downtime.