Is it possible to create a hybrid from on-premise Exchange to 2 separate 365 tenancies?

Brass Contributor

I am working with a customer, a college, where they currently use a single AD/Exchange Forest running as a hybrid to a 365 tenant.  The setup includes two separate colleges, managed by a single IT team, which they now want to separate into 2 tenants, but retaining a single on premise AD

I know we can split OUs and sync different areas of one AD using AAD Connect to the 2 tenants, but I have seen conversations that you can only run a hybrid to a single Exchange tenant from our on premise forest.  Has anyone tried this?

If I can't run the HCW twice, once for each tenant, I can't see how I will be able to create/manage users in the non-hybridised tenant?


5 Replies



EDIT - I posted this and then realised you were asking for the opposite.  Sorry about that.



An older article on the subject -


Have not been able to find much else, and it's not a scenario I've ever tried or considered.  Whether or not it is possible however, I don't think it's particularly desirable.  Happy to be corrected if anyone knows better though of course.

Hi Andy,

On the technical side, yes it's possible but you will need to create everything manually from the inbound and outbound connectors to the organization trusts and mailbox aliases. As you said yourself the HCW takes care of this and Microsoft won't support this kind of scenario as well.

Hi Andy,


If you have one Active Directory and you configured 2 UPN Suffixes (Domains) on that Active Directory, and you need to have O365 tenant for each UPN suffix separately. Yes you can. 

You have to install 2 VMs or servers in your on-premises infrastructure and Install 2 Azure AD Connect servers and link each Azure AD Connect server to one of the UPN suffix and link each Azure AD Connect server to an O365 tenant. 


You have to be sure the following


1) you configured each Domain on a separate O365 tenant and the domain is verified. 

2) To have the appropriate licenses>