Overflow Capability to View-Only Attendees Available for Large Teams Meetings

Get to Meeting Capacity and Then Overflow

Flagged in MC240169 on February 17, Microsoft has confirmed that the Teams view-only meeting experience to allow participation of up to an extra 20,000 people in a meeting is available worldwide. The 20,000 limit is temporary which Microsoft plans to reduce to 10,000 on June 30, 2021. This capability was originally launched in August 2020 as part of the Teams advanced communication license. It’s interesting that Microsoft now includes the feature in mainline Teams, perhaps because of demand created by many large organizations using Teams for corporate communications during the pandemic.

Attendees for regular Teams meetings enjoy access to the full interactive meeting experience, including meeting chat, file sharing, polls, reactions, and so on. Currently the interactive limit is 300 for commercial tenants and 250 for GCC. According to Microsoft 365 roadmap item 65951, the limit will soon increase to 1,000, a fact confirmed by multiple references in Ignite 2021 announcements and subsequently in MC242587 for deployment from early-April with worldwide availability expected by mid-April. The new limits apply to tenants with Office 365 E3/A3 and E5/A5 plans.

Whatever the current limit is, once the capacity of a meeting is reached, new attendees are limited to view-only. They can see the video feed for the active speaker and listen to active participants. View-only attendees can’t use the gallery, large gallery, and together mode views. They can also see any content shared through desktop sharing.

The effect is that you have a hybrid meeting of active and view-only attendees composed of a regular meeting and a streamed session. Sometimes the feature is referred to as an “overflow room” like those used for popular sessions at in-person conferences.

Letting People Know What’s Happening

When the limit is reached, the meeting organizer and presenters see a banner saying that the meeting is at capacity. At this point, if allowed by the Teams meeting policy assigned to the organizer’s account, Teams allows new attendees to join the meeting in view-only mode. These attendees are informed that the meeting is at capacity and that they’re joining in view-only (Figure 1).

A user is told that they must join a Teams meeting as a view-only attendee
Figure 1: A user is told that they must join a Teams meeting as a view-only attendee

View-only attendees can join using any Teams client, including mobile devices. However, they can’t join from Microsoft Teams Room systems or Cloud Video Interop (CVI) services because these features need updates to support view-only attendance.

Important for Administrators

People in the meeting do not see view-only attendees in the participant list, which means that organizers and presenters can’t remove a view-only attendee from a meeting. In addition, Teams doesn’t record their details in the meeting attendance report.

The lack of visibility for view-only attendees means that presenters need to be careful about who is invited to meetings and meeting settings for the lobby. Remember, anyone who has a meeting link can attempt to join that meeting, and if the meeting settings allow joining without pausing in the meeting lobby, someone you might not want to be in a meeting could be able to join. Teams makes sure that view-only attendees comply with lobby restrictions, but it’s always a good idea to check meeting settings and confirm that the correct lobby joining option is in place for any meeting where confidential or sensitive information is discussed.

No Automatic Promotions

People join and leave meetings as they progress. If some with the full experience drop out, the meeting has available capacity. However, Teams doesn’t promote view only attendees to active status. Instead, these people must leave and rejoin the meeting to enjoy full participation.

Teams Meeting Policy and License Requirements

The ability to have a meeting spill over into view-only is limited to meetings organized by accounts with Office 365 E3, E5, A3, or A5 licenses and a Teams meeting policy with the StreamingAttendeeMode setting enabled. By default, Teams meeting policies have this setting disabled, so if you want to use the feature, you need to update the policies assigned to the accounts who will organize large events.

For now, you can only update StreamingAttendeeMode using PowerShell. For example, here’s how to connect to the Teams module to update a meeting policy:

Connect-MicrosoftTeams
$SB = New-CsOnlineSession
Import-PSSession $SB
Set-CsTeamsMeetingPolicy -Identity "Allow Meeting Recording" -StreamingAttendeeMode Enabled

Update March 6, 2021: Microsoft has updated the Teams PowerShell module to V2.0. In general, it’s best to use the latest version of a module but test it first! This version doesn’t require using New-CsOnlineSession to connect to the management end point.

Like all Teams policies, it can take several hours before the policy change is effective. Microsoft says that they will update the Teams admin center to support this update for meeting policies in the future.

Streaming Meetings

As the setting name suggests (and confirmed in MC240169), Teams uses the streaming technology for Live Events to serve view-only attendees. This means that an inbuilt delay of 30 seconds is used to allow the technology to capture, process, and then stream the meeting. In other words, view-only attendees are always behind what’s happening live in a meeting. And like Live Events, view-only attendees see live captions (only for English).

Popular with Large Organizations

According to Microsoft’s FY21 Q2 results, 117 organizations have more than 100,000 Teams users and 2,700 have more than 10,000 users. Microsoft has experienced a 50% growth in both categories since July 2020 and large enterprises form a huge and important sector within the overall 115 million Teams active user base.

These organizations are the target market for view-only meetings. They accommodate scenarios like corporate announcements, product launches, and briefings. Teams Live Events will continue alongside because these events allow more control over the production of video content, but I’ll bet that view-only meetings will be good enough in many circumstances.


Change continues and new features appear across Office 365 in a constant flood of tweaks and updates. Subscribers to the Office 365 for IT Pros eBook receive monthly updates to make sure that they keep pace with new developments. Shouldn’t you take advantage of this resource?

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