Our company has recently merged, combining 300 employees from our firm with 130 from another. Both groups operate on Microsoft 365, and each believes their current setup should be the standard moving forward. This has resulted in two separate Global Address Lists (GALs), and it's become a challenge—management struggles to find individuals from the other firm without involving IT. Clients are frustrated as well, as they can't locate their contacts.
Realistically, we foresee a complete tenant merge taking at least 6 months due to compliance requirements and data mapping tasks. In the meantime, we need to figure out how to sync the two M365 tenants to a unified address book without undergoing a full migration. What are our options for ensuring that both directories are accessible on employees' phones (since many prefer calling over checking emails) while preventing users from making unwanted changes in the GAL?
5 Answers
I highly recommend MTO as a quick fix while you plan the larger move. The cross-tenant GAL sync is a straightforward way to resolve issues immediately. Planning for the full migration could take around 6-9 months, though—just a heads up! And definitely involve your legal team early for decisions about which domain to keep; that can get complicated.
For your situation, Multi-tenant Organization (MTO) seems like the best solution to facilitate collaboration right away. You mentioned a waiting period of 6 months for a full merge, but MTO can provide that quick fix. It won’t require a full tenant migration, and it should enable users to find each other without hassle. I believe it can integrate with iOS/Android address books, right? That way, everyone can connect without needing to dive into Outlook all the time.
Yes, it supports syncing contacts directly to the native address books, making it super user-friendly.
You can actually address this right from the Exchange admin center. Just set up organization sharing between the two tenants. That way, everyone can see each other's info without needing a full migration right now.
I’ve set up MTO recently, and it's surprisingly straightforward! You have the option to modify display names in the GAL to differentiate users from both companies. While chats and teams will still be separated initially, MTO helps eliminate the confusion—your team won't have to deal with the annoying 'I can’t find anyone' issues after implementation. Plus, if you do go for a complete merge down the line, you can easily revert if needed!
As an interim solution, consider creating external contact cards for users from the other tenant. It requires a bit of exporting and command-line work, but it would resolve the GAL issues temporarily. However, be aware that some cleanup will be necessary later when the full merge happens.
Why go through all that hassle? MTO handles all that for you, and it’s less work in the long run!
You nailed it! MTO really simplifies this process.