We currently have two separate Office365 tenants (contoso.onmicrosoft.com and fabrik.onmicrosoft.com), each associated with its own AD forest (contoso.int and fabrik.global). The 2 on premise AD forest currently does not have cross forest trust in between. The plan is to consolidate the two tenants into one of the existing tenant (contoso) without consolidate the on premise AD forest. Based on MS doco https://docs.microsoft.com/en-us/azure/active-directory/hybrid/plan-connect-topologies we will add fabrik forest into the current AD Connect, so its objects can be synced into Contoso's Azure AD. One thing is not clear to me is whether we need to setup cross forest trust in order for this to work. Can anyone confirm if cross forest trust is a must for the consolidation to work?