Guest Users Microsoft Teams

Microsoft Teams Guests Explained

In this post, we are going to explain everything you need to know about Microsoft Teams Guests

What are Guests?

Guest users are accounts that do not belong to the company’s tenant. They are invited to a specific team/s.

These users will be able to communicate in the following scenarios:

  • Become Guest members of Channels – they will not see any other channel
  • Participate in a private chat
  • Post, delete and edit messages
  • Share a file from a channel

How to control the guest user capabilities?

Once you are logged into to the Office admin portal, click on Teams in the sidebar below Admin Centers

In that page, you can configure which features should apply to guest users.

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How to identify a guest account?

1- In the members’ view of a team/channel it explicitly mentions which user is a guest:

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2. In the users’ view of Office 365, users who follow this syntax is considered as a guest:

For example:

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For a full list of capabilities and limitations please take a look at the following document:

1.A guest user can find all users from the Office 365 tenant domain and chat with them


  • When one invites a guest into a channel, permission is given to contact anyone in theorganization in a Peer to Peer session. Thus, the company users can be subjected to harassment or a violation of conflict of interestThere is also a lack of visibility on guest actions.
  • When one invites a guest to a channel, permission is also given to contact other guests in the organization in a Peer to Peer session. Thus, the other guest users can be subjected to harassment or a violation of conflict of interest.When the organization users are joined as guests to an external organization, they can share information. Thus,the company can be subjected to data leaks and intellectual property loss.


In order to solve many of the risks of having guests, microsoft offers their solutions via their product called Information Barriers (here you can see a blog with all the capabilities and limitations)

Here at AGAT Software, we offer SphereShield, asuite of compliance and governance solutions for Microsoft Teams. To learn more, visit the Ethical Wall page

Use caseMicrosoft Native CapabilitiesSphereShield
Limit a guest to only contact a specific  groupAvailable in information BarriersAvailable in Ethical Wall
Limit  a guest to only send files to a specific groupNot availableAvailable in Ethical Wall
Limit a guest to only share screen with specific groupsNot availableAvailable in Ethical Wall
Prevent internal users from sharing files when they are guests in other organizationsNot availableAvailable in Ethical Wall
Prevent internal users from sharing sensitive information when they are guests in other organizationsNot availableAvailable in Sphereshield DLP

Guest Access to Specific Teams

Here we offer a few resources on different solutions to prevent guests from being added to specific groups. Some of the solutions may be difficult to implement.

Governance Guest Users Microsoft Teams

How to prevent users from becoming Guests in an external Office 365 Tenant

How to block your users from joining other external Tenants as Guests

Microsoft Teams is without any doubt a key asset for corporate communications at this time. To improve collaboration Microsoft offers the ability to add an external user as a guest in the external tenant.

This increases productivity but on the other hand can pose new risks especially when your users are guests in other tenants and at that point are not subjected to the policies of your company.

The guest option is actually a loophole in compliance and governance of a company that must be addressed.

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The problem 

Scenario: An internal user (let’s call him “employee”) joins an external Tenant (another company) as a Guest.

The risk associated with this scenario is enormous. For instance, as mentioned in this article Microsoft DLP policies won’t apply, which can mean data leaks without any prevention.

Another example is that companies might disable some capabilities in Teams for compliance reasons like file sharing. These policies will not apply when your users are guests in other tenants.

How to solve it

SphereShield Ethical Wall for Microsoft Teams offers such ability as part of the Teams governance / Ethical wall capabilities. By setting a rule the administrator can just block all or a specific group of employees from communicating in any form with an external tenant.

In addition it can set unlimited rules controlling communications between users (or groups) and internal users, groups or external users (or domains). 

SphereShield also offers the ability to prevent users joining meetings anonymously 

If you want to know whether SphereShield Ethical Wall is suitable for your business, contact us today. A free demo is available.

Guest Users Microsoft Teams

Everything you need to know on granting external and guest access in Microsoft Teams.

In this article we’ll explain to you in a very simple and concise way everything you need to know on external and guest access for Microsoft Teams, plus a lifesaving tip to increase productivity in this platform.

1-External Sharing

1- External Sharing: gives you the chance to communicate through chat, and coordinate meetings with a common calendar. Also, it is handy sharing documents, files, libraries and event complete sites by SharePoint Online. This feature is the best option to collaborate with someone outside your institution, when you invite him this member becomes a guest access. 

Now let’s dig into this type of access and its characteristics. Allows you to invite external users to become members of your team, which means you are giving access to an individual and not to a domain.  

So, what are the permissions for a guest access? 

  • They will have the capability to create channels, and share the channel files 
  • Can participate in a channel conversation, and private chats  
  • Be able to post, delete, and edit messages 

Permissions of Team Members and External Users with Guest Access

2- How to enable guest access in Microsoft Teams? 

In teams guest access is turned off by default and the only way to enable it is to be an Office 365 global admin. These are the following steps you need to go through:  

  • In the Microsoft Team Admin Center go to Org – Wide Settings and tap on “Guest Access” 

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  • Switch the “Allow guest access in teams” to ON and click save (Can usually take up to 24:00 hours for changes to become effective) 

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3 – Configure guest access in Microsoft Teams

This is a vital section of the setting up phase, because here you will manage what the guest will be able to see and do. In the same spot where we allowed guest access you can configure the settings for (Calling, Meeting and Messaging). Leaning on what you want to allow by clicking on or off and afterwards save it so it applies to your new settings  

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Remember guests once in the team can get access to all public channels, be aware.

Also a guest is not limited in actions (file sharing, calls, etc.)

4 – Now it is time to start adding some guests !!  

Only Team Owners can add guests in teams. Firstly, make yourself an owner of a team in (Teams > Manage) and start adding new users 

  • In the teams app on the left sidebar select “Team” and go to the team you want to add a guest  
  • Select more options and click on add a member  
  • Introduce the guest email address, afterwards click save and your guest will receive a welcome invitation email  

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With guest access your content never leaves your sight, because all your data gets saved on your tenant. Here you can protect it, oversee it and manage it. Different projects require different needs that’s why it’s essential to educate your users in order to have a secure environment where your data is secure.  

How to solve the issue with guest access being able to participate in every channel?

There is bad news and good news with this respect. The bad news is that this kind of control is not possible within the platform itself.

The great news is that AGAT has the simplest way to manage guest access into Microsoft Teams. Sphereshield for Microsoft Teams offers, amongst its complete suite, the possibility to get a granular customization on guest access and define which channels a guest can and can’t do.

To get a FREE live demo, contact us today.

Most of the content in this article was retrieved from

For more information on the capabilities and limitations of Microsoft Information Barriers read this post ->