Impact of changing our primary domain

[AMcCain]

When we first set up our tenant, we left the [randomname].onmicrosoft.com domain name as the primary since we weren't using the email portion of the tenant.  We did set up our real domain as a verified domain.  Now we would like to make our real domain the primary but are not sure of the consequences of that step.  We're looking to start using Teams and the corresponding document libraries as we migrate away from normal server storage and want to resolve any issues up front, is possible.  Here are my assumptions and questions.

• Since we are syncing on-prem with AAD, I know we can change the UPN of everyone to the primary domain.  That will fix the users.
• Will this change the URL paths to any SharePoint or OneDrive sites?  When we've changed the UPN for some in my department, it broke the links to their OneNote notes and it took some fiddling to get it straightened out.  This might also affect anyone who is trying to open a file from their recent documents list, assuming the path to that file has changed.
• Right now our real domain is set as Federated and Verified.  It looks like we'll just need to go in and make it the primary.
• We have single sign-on working for Office apps on domain computers.  I assume that will continue to work.
• Any other gotchas we need to be concerned about?

Thanks for any assistance!

Alan

[#2]

Hi Alan,

It will change OneDrive and SharePoint urls, it gets disruptive to the users in some cases, do you use Exchange online as well? You need to change the proxyaddress to reflect new primary domain.
I don’t expect you have issues with Federation after changing to the new primary domain. PCs may need reboot or sign out and sign back in.

Sharing this post and hope it helps! Good Luck

https://techcommunity.microsoft.com/t5/office-365/impacts-of-changing-default-domain-in-office-365-t...

[#3]

@Moe_Kinani Thanks!  We're not using Exchange so that's one less thing to fix.  It's mostly users accessing documents in their OneDrive via Word and Excel.  It will just take some education on our part about the change.

[#4]

OneDrive syncing folders should be good after sign out and sign back in.

Thanks!
Moe

[#5]

@AMcCain I've done this before, in my experience the only impact is:

- Office apps - sign out and sign back in again to see the new UPN or if there are activation issues

- Onenote - since the path changes, notebooks become disconnected. If possible get the users to close the notebooks before the change, then open after. Otherwise you can end up with changes that have not synced which can get messy.

[#6]

I am doing a POC for federation now and had issues with primary domain.

What I found is:

Primary domain can only be managed domain, you CAN'T make a federated domain as primary domain.

https://docs.microsoft.com/en-us/azure/active-directory/enterprise-users/domains-manage
"You can change the primary domain name for your organization to be any verified custom domain that isn't federated."

[#7]

Hi, you can check and change the SharePoint domain name efficiently using PowerShell! Refer to the below blog post to know the impacts and limitations on SharePoint domain name change.

https://m365scripts.com/sharepoint-online/a-guide-to-change-sharepoint-domain-name-using-powershell/