Use of Teams apps for external attendees or guest from outside an organization

Teams apps allow collaboration with people outside your organization. As an admin, you control who can access Teams chats, meetings, and channel to collaborate with your organization's users. For detailed information, see how to allow collaboration with external attendees and what can guests do in Teams. This article focuses on use of apps by people outside your organization.

The following types of users can be present in a Teams chat or meeting and if you allow it, they can use apps in Teams.

  • A guest user is someone who isn't an employee, student, or member of your organization. They don't have a school or work account with your organization.

  • An external (federated) user is from another domain and doesn't have access to your organization's Teams resources.

  • An anonymous user is a user who joins a meeting via a link. The user isn't logged in with their Microsoft account or their organization’s account.

For a more detailed comparison between guest and external users, see communicate with users from other organizations.


Install, update, and delete apps for guests

Guests can't install, update, or delete apps into a shared context, such as a chat, channel, or meeting. Guests can do so in their personal scope using message extensions and direct links. Guests can't access the Teams app store from the Teams desktop app, but can access the store with a direct link.

Usage behavior and policy for guests

Guests can use an app if the app was installed by an organization's user.

Bots installed to a channel

Guests can mention the bot and interact with adaptive cards.

Personal bots installed with policies

  • For any app, guests adhere to global and org-wide permission policies set for the host organization. If an app is blocked for the whole host organization, then guests can't use the app either.
  • Any bot included in the global default app setup policy will also be installed for guests.
  • After a bot is installed, bots and guests can proactively communicate with each other.
  • You can't remove a guest from the global default app setup policy.
  • To avoid guest from accessing bots, you can create more app setup policies, assign them to internal users, and install bots with the custom policies.

Federated users

Install, update, and delete apps for federated users

Federated users can't install, update, or delete apps into any context, such as a personal, chat, channel, or meeting. They don't have access to the Teams app store of the hosting organization.

Usage behavior and policy for federated users

  • People from other organizations adhere to the hosting organization's global (org-wide default) policy
  • Users in the hosting organization can add apps in meeting chats with people from other organizations. People from other organizations can't add apps in meeting chats but can interact with bots, tabs and message extensions once added to the chat.
  • After a bot is installed in a meeting chat, it can proactively communicate with people from other organizations in that chat, and those people can communicate with bot.
  • The data policies of the hosting organization are applied.
  • The data sharing practices of any third-party apps shared by that user's organization are applied.

Anonymous users

Install, update, and delete apps for anonymous users

Anonymous users can't install, update, or delete apps in meetings.

Usage behavior and policy for anonymous users

Anonymous users can't directly use apps in meetings. If an app sends an adaptive card in the chat, anonymous users can interact with the card. Such users can interact with apps in Teams meetings if the user-level permission policy enables the app. Anonymous users inherit the user-level global default permission policy.

Anonymous users can interact only with the apps that are already available in a meeting but can't acquire and manage such apps. The native users can continue to use meetings apps even when the anonymous users are attending a meeting.

Allow anonymous users to use apps in meetings

By default, anonymous users can interact with the existing apps in a meeting. Anonymous users cannot add new apps to a meeting. You can disallow anonymous users for interacting with apps.

  1. Sign in to the Teams admin center and access Meetings > Meeting settings.

  2. Under Participants, change the toggle for Anonymous users can interact with apps in meetings to Off.

  3. Select Save.