This guide documents the setup required to enable support for Planner meeting rooms in complex, multi-tenant environments. The configuration allows users from multiple subsidiary companies or sister organizations (connected to different Active Directory tenants) to seamlessly access Meetings and book resources via the modern Microsoft Outlook Add-in.
Why is this valuable for Multi-Company Organizations?
This deployment is essential for multi-company organizations and those managing multiple Microsoft Exchange tenancies because it:
Unlocks Adoption: It resolves key technical limitations (a "functional deficit") that previously prevented the modern Outlook Add-in from being fully adopted in multi-tenant environments. This is critical for getting your entire workforce onto the centralized Meetings platform.
Simplifies Deployment: It standardizes and simplifies the rollout of the booking tool across all your subsidiaries and partner organizations.
Future-Proofs Your IT: This configuration supports your organization’s transition to modern Microsoft architectures, providing greater flexibility in managing users across federated and hybrid IT environments. In short, it helps your organization adopt the latest, most secure cloud services faster.
Target Audience and Context
This documentation is written from the perspective of an organization that is already running the Meetings solution and is now looking to expand their environment by adding additional Microsoft Exchange tenants.
Section 1: User Provisioning
User provisioning can be completed either manually or through the Active Directory (AAD) import process.
Section 2: System Integration
The following steps connect the administrative user and system components.
Navigate to Administration and select Integrations.
Click Calendar Synchronization.
Connect the Calendar Service to the primary tenant to ensure proper scheduling and availability synchronization.
Click on Outlook Add-in.
Click Grant Admin Consent to all tenancies that will require access via the Outlook Add-in.
Each granted tenant will be listed in the grid.
The left column indicates the Tenant ID. The Tenant ID for a tenant can be found by viewing the Microsoft Entra Overview page.
For all non primary tenants the Calendar Service must also be connected. Click on the Connect button to Grant consent in a similar way to the Outlook Add-in.
Note - The Calendar service is connected when the Calendar service status column reads Reconnect.
Section 3: Outlook Add-in Deployment
This section covers the setup and installation of the Outlook Add-in for end-users.
Download the latest version of the Outlook Add-in installation package from Administration - Integrations - Download manifest
Install the Add-in on the user's local machine or deploy it centrally across the organization.
Section 4: Verification and Testing
Use these steps to confirm the end-to-end functionality of the system and the Outlook Add-in.
Open the newly installed Outlook Add-in.
Create a new meeting or booking using the Add-in interface.
Navigate to the Planner Web product.
Confirm that the booking created in step 2 is correctly synced and reflected in the Planner.
Edit the booking details (e.g., time, attendees, or title) directly from the Planner interface.
Open the booking again via the Outlook Add-in.
Confirm that the edits made in the Planner (step 5) are reflected correctly within the Add-in.
Note - Only Planner Rooms will be visible to users in the Outlook Add-in for child tenants. This is as expected. The ability for planner to book exchange rooms across tenants is an upcoming feature.