Applies To

Call2Teams - Customers


Where there is a need to synchronise large user numbers into the Call2Teams portal, the Large Tenant Mode provides a mechanism to reduce the scope of the sync process to a subset of users. This can significantly improve the performance of the Sync Now process.

Large Tenant Mode is intended for user management above 1000 users.

If the customer account has fewer users than this then there is no need to use this function, however it will still work. 

Important Note For Administrators:

In Large Tenant Mode the Sync Now function does not perform the same licence checks and validation that would otherwise take place for a regular Sync, as this is time consuming and could cause the Sync Now process to time-out in very large customer scenarios.

Use of Large Tenant Mode assumes the groups being synced are properly licenced with the Phone System licence and do not have a calling plan. 

If this is not the case, then users will be unable to make/receive calls and existing calling plans can be disrupted.


To understand more about Azure Active Directory groups used by Large Tenant Mode, please review this article:

For more information on group-based licencing for Azure and Office 365, please see this article:

  • Basic security groups are supported with Large Tenant Mode. 
  • All members of the groups chosen will be be present in the Add User list or available to be matched by the bulk import function.
  • The group select option supports transitive membership, so the group can contain other groups and the service gets all of the implied users of the sub-groups.

Configuring Large Tenant Mode

1. Large Tenant Mode is accessed from the Teams Services tab

2. Click the toggle to enable Large Tenant Mode.

3. When enabling Large Tenant Mode (and requesting any subsequent changes), Microsoft will need permission to read groups from the customer's active directory:

4. Grant this permission to allow Large Tenant Mode to view the list of available directory groups:

6. Select the groups that contain users to be enabled on the service. Multiple groups can be added.

7. Review the selected groups and save the settings to complete the set-up of Large Tenant Mode:

Management of Large Tenant Mode

At any stage additional groups can be added using the Choose Groups link.

To remove a group, select to delete them from the list:

Note: Take note of the warning when deleting groups as deleting a group will cause users in that group to be deleted at the next sync.

Large Tenant Mode and Phone App

When Enabling Phone App & Large Tenant Mode, there will be an additional menu, which is different to the standard user menu.

Users need to select a group or groups under the Azure AD Phone App Groups for Phone App.

Azure AD Phone App Groups will only be visible once Phone App is enabled:


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