Guest users can participate in conversations, but cannot access files

Frequent Contributor

One of our customers uses Microsoft Teams as their chat-based workspace. They can create teams, add channels, discuss in conversations and share files with each other, all within Microsoft Teams. Recently, they decided to start working with other companies using Microsoft Teams. However, after sharing a team, the guest user has only access to the team channels, switch between the tabs, and participate in conversations. The guest user cannot open files shared in a chat, he receives the error message "You don't have access to this file.". When the guest user switches to the Files tab, he cannot see any document, only the error message "You don't have access to these files". Opening the SharePoint site as the guest user results in the error message "You need permission to access this item". The SharePoint settings seem to support external sharing. Attach files provide screenshots from the guest user's Team environment, and the Teams / SharePoint sharing settings.


We were able to reproduce this error for new teams, for each invited guest. Steps to reproduce:

  1. Create a new team as an employee
  2. Add some documents as an employee
  3. Add guest user to the team
  4. Let guest user accept the invitation to join the team
  5. Let guest user sign in to Teams and let him open the team. Browsing the channels, the tabs and posting messages works
  6. Let guest user click on a document mentioned in a conversation, results in the file access-error message
  7. Let guest user click on the files tab, which results in the files access-error message
  8. Let guest user click on Open in SharePoint, which results in opening the browser with the error message "You need permission to access this item"

Any ideas on how to make collaboration with guest users working?


Guest user in Team-Conversations.pngGuest user in Team-Files tab You don't have access to these files.pngGuest user in Team-Open document from teams conversation.pngGuest user in Team-Open SharePoint site-You need permission to access this item.pngMicrosoft 365 Admin-Sharing settings.pngSharePoint Sharing settings.png

10 Replies
While I have seen this issue before, It could be just a question of time that SPO gets aware there are new guests users in the team...if the guest users were added some time ago, then this is not working as expected and you will have to open a support ticket in the tenant and if possible, share your ticket ID here so I can involve the right guys in this thread
best response confirmed by Harold van de Kamp (Frequent Contributor)

We managed to get this working by changing the Office 365 Groups sharing settings. Below you can find the Office 365 Groups settings resulting in the issue and the changed settings which resolved the issue.


Office 365 Groups settings, resulting in the issueOffice 365 Groups settings, resulting in the issueChanged Office 365 Groups settings, resolving the issueChanged Office 365 Groups settings, resolving the issue

I cannot find where these settings are to review and change them. If you can provide a path to the right settings it would be appreciated.
Thanks @Harold van de Kamp and @Juan Carlos González Martín 

This setting is in the admin portal! Services and add-ins -> groups


@Harold van de Kamp Hey Harold (and anyone following) - I've been following the guest user scenarios for years now and have occasionally contributed with answers and blog posts.


Today, I published a blog post rounding up the most frequent questions I get asked and the most Googled queries. You can find it here.


Disclaimer: I am affiliated with Mio who offers a solution to one of the problems in this post.

@Harold van de Kamp  I know this is an old thread, but still very relevant as organisations expand their understanding of Teams and external / guest users.  If anyone is experiencing this kind of issue (or any other sharing issues), there's a number of places to check:

  1. Microsoft 365 Admin Center > Settings > Services
    1. Office 365 Groups
    2. Security & privacy (tab) > Sharing
  2. Teams Admin Center > Org-wide settings
    1. Guest access (what they can & can't do)
    2. External access (there could be a whitelist of external domains which your internal users can communicate with)
  3. SharePoint Admin Center > Policies > Sharing
    1. Various settings for sharing content
    2. Pay particular attention to the "More external sharing settings" drop-down.  Again, there could be a whitelist of external domains which your internal users can share with.  It's perfectly feasible to have an external Guest in a Team who can participate in conversations fine, but if the "Limit external sharing by domain" setting is ticked and their domain isn't included, when they click on the Files tab they'll get an error.

Hope this helps.

@Oz Oscroft  I have tried this and still guest users are not able to access files.


is there actually a conclusion for this topic?

For me, all settings are set. But still our guests can not see the files tab.

Thanks for a short feedback - if there is no, I would create a microsoft ticket and ask them directly.



@keptenkrems This is what I finally did. I did not see this documented anywhere so I make no promises other than it allowed me to give guests access to Team files... Goto SharePoint admin, Sites, Active sites, click the Team, Policies, 'Edit' External sharing, choose either 'Anyone' or 'Existing guests only' depending on what you want. Save

@Joe76  I was able to get the Guests access to shared content by modifying the site permissions on SharePoint Online. Check this