Manage Teams guest access

[rs_oakford]

As I understand, Guest access for Microsoft Teams is currently off by default for any given tenant - see https://docs.microsoft.com/en-us/microsoftteams/set-up-guests.  However, it's not clear whether a given tenant has Guest access setting set to "Off" instead of "Service default" based on the information and screenshot in https://docs.microsoft.com/en-us/microsoft-365/solutions/collaborate-as-team#teams-guest-access-sett....

1. Is it possible to check whether a given tenant has Guest access disabled (Guest access setting is set to "Off" instead of "Service default") via PowerShell or using an API?  As I'm managing hundreds of tenants, I would like to know a way to check this without having to sign into each Teams admin center individually.

2. If I do have to check this manually for each tenant, how do I distinguish in the Teams admin center whether the Guest access setting is set to "Off" instead of "Service default"?

I realize I can check Guest access and disable it for individual Teams as shared in https://techcommunity.microsoft.com/t5/microsoft-teams/allow-or-block-guest-users-from-a-specific-te...- assuming this is still current.

<#
Configuration Change in Guest access for Microsoft Teams 
MC228482 

	Major update: Announcement started	
	Applied To: All	

We're making some changes to the default setting for Guests in Microsoft Teams
Beginning on February 8th, 2021, we are turning on Guest access in 
Microsoft Teams by default for any customers who have not configured 
this setting. This will bring Teams Guest capability into alignment with 
the rest of the suite, where the setting is already on by default. 


[Key Points:]
•	Timing: February 8th, 2021
•	Admin control: Admin center UI
•	Action: Review and set appropriate configuration
[How this will affect your organization:]
When this change is implemented if you have not already configured Guest 
access capability in Microsoft Teams, that capability will be enabled in 
your tenant. With guest access enabled, you can provide access to teams 
and other resources to people outside your organization while 
maintaining control over your corporate data. 


[What you need to do to prepare:]
Prior to this change taking effect on February 8th 2021, if you want 
Guest access to remain disabled for your organization, you will need to 
confirm that the Guest access setting is set to "Off" instead of 
"Service default". Instructions for how to configure the Teams guest 
access settings can be found here: Teams guest access settings 
[https://docs.microsoft.com/en-us/microsoft-365/solutions/collaborate-as-team#teams-guest-access-settings] 


#>

[#2]

1. Good question! Don’t know and have not given it any thought until now.

2. You’ll see On, Off and Service default: Off if I dont recall wrong. Can’t check now.

btw, if you’re using On or Off you don’t have to worry about the change. As On is already allowing guest access and Off is to ”opt-out”.

[#3]

Thank you for your reply, @ChristianBergstrom .

2. With regard to distinguishing in the Teams admin center whether the Guest access setting is set to "Off" instead of "Service default", I created a new tenant and can confirm:

https://admin.teams.microsoft.com/company-wide-settings/guest-configuration shows:
"Service default: Off"

[can't seem to "insert photo" screenshot in post so see attached]

... now to find out whether this is exposed via PowerShell anywhere.