GAL Federation between different O365 tenants
As organisations grow, or have to separate different business areas in different O365 tenants it would be useful to be able to share or federate global address lists between different tenants. The only current choices are:
Create contact objects in tenants which are then disconnected from the original user - this means if the user details change the contact in the other tenant becomes out of sync.
Where domain federation in in place and directory synchronisation services running for each tenant, create on premise AD users as mail enabled users and ensure each directory sync for each tenant looks at the other domains. This will ensure that user objects are sync'd to the other tenant as mail contacts.
The second method works quite well from a point of ensuring that user details are always accurate with AD objects but only works in an environment where domain federation and dirsync are used. This is not an option in a completely cloud based environment.
Allowing GAL federation/sync between tenants would reduce on premise administrative burden and also provide a solution for cloud only adoption.
Moja firma posiada 3 spółki o Office 365 dla każdej z osobna jedną Domenę AD lokalną z sync'iem zakładanie dodatkowo kontaktów w pozostałych office 365 jest upierdliwe i czasochłonne :(
As a twinned agency (2 separate agencies with a common IT structure), this is a must have. Currently we work around this by adding contacts from the other agency to our own GAL.
Create user in Agency A, create contact in Agency B.
Duplication of work is not a good thing.
While we're at it, Resource sharing would be a good thing also, since we share the same conference rooms, video equipment, etc.
As a state agency being able to federating the GAL would be very useful. Without this feature our State is looking to go to GMail as a state wide email system.
A Afonin commented
удивлен что нет такой функции изначально. очевидно же что, один админ будет иметь несколько организаций, акаунтов в office 356.
My company manages multiple tenants that collaborate. Federating the GAL would be immensely helpful.
Mike Fawazz commented
My company has to manage multiple hosted tenants for multiple entities under our ownership umbrella (no on-prem Exchange). However, these multiple entities also regularly collaborate for their business operations. It would be nice to be able to federate GAL, Skype, Calendars, etc... across tenants.
Michael Fagan commented
Not only federation between tenants but also a smooth way to migrate from tenant to tenant. So far the TechNet articles that cover tenant to tenant migration explain "use a 3rd party tool".
This relates to O365 Skype federation with on-premise federation partners - it is not possible to synchronize their SIP address using Azure AD Connect - see here: https://office365.uservoice.com/forums/273493-office-365-admin/suggestions/15521445-azure-ad-connect-sync-contact-objects-including
Craig McCollum commented
I have need of this as my company is part of a group that needs to improve levels of communications
This. Is. Really. Important.
It should be possible to federate cross-tenants as seamlessly as possible. I don't know if Azure AD B2B will help or go what distance in realizing this. But, sharing contacts is unwieldy.
I, as many others are, am also seeking to share GAL between two O365 Tenants. Based on my research Microsoft does not provide a way to do this as the OP has pointed out. The workaround (#2 above) has potential as long as your two orgs have on prem AD and can be connected in some way (VPN/MPLS/etc).