Teams Issues

Question

Hello

Please i need your help on this issue.

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Answer 1

Hi @Rita Rita, 

Welcome to Microsoft Q&A forum. 

Thank you for reaching out regarding the issue where guest users are unable to share files in Microsoft Teams. Based on your description, I’d like to provide the following information. 

 

Your guest users have been added to Teams but are encountering permission barriers, which usually occur due to the following reasons: 

• Guest Access not fully enabled in Teams: If Guest Access is disabled in the Teams Admin Center, guests will have limited functionality (no chat, calls, or file access). 
• External sharing restrictions in SharePoint/OneDrive: If sharing is restricted to internal users only, guests cannot upload or share files in Teams. 
• Group or directory policies blocking guests: Microsoft 365 Groups or Azure AD policies may prevent guests from accessing files even if they appear in Teams. 

 

To enable file sharing for guest users, please follow the steps below. Kindly note that some of these settings require administrative privileges. If you do not have admin rights, please contact your organization's IT administrator for assistance. 

1/ Enable guest access in Microsoft Teams 

• Go to Teams Admin Center → Users → Guest Access. 
• Turn on Allow guest access in Teams. 
• 
• Configure permissions for chat, calls, and messaging as needed. 
  Note: Changes may take up to 24 hours to apply. 

2/ Allow guests in Microsoft 365 Groups 

In Microsoft 365 Admin Center → Org Settings → Microsoft 365 Groups, enable:  

• Let group owners add people outside the organization to groups. 
• Let group members outside your organization access group content. 
•  

3/ Configure external sharing in SharePoint and OneDrive 

• In SharePoint Admin Center → Policies → Sharing, set sharing level to New and existing guests. 
• 
• Enable Allow guests to share items they don’t own if you want guests to re-share files. 
• 
• Check domain allow/deny lists to ensure guest emails are not blocked. 

4/ Review Azure AD external collaboration settings 

• In Azure AD → External Identities → External collaboration settings, confirm that guest invite restrictions are not blocking access. 
• 
• If using Cross-tenant access or B2B Direct Connect for shared channels, verify reciprocal settings between tenants. 

5/ Add guests and test file sharing 

• Invite the guest to the team and confirm they appear with the “(Guest)” label. 
• Test file upload in the channel’s Files tab. 
• Note: Guests cannot attach files in private chats because they do not have OneDrive in your tenant. Internal users can share files from their OneDrive with guests if external sharing is enabled. 

Additional considerations 

• Channel Type: Standard and private channels use SharePoint sites; shared channels require B2B Direct Connect. 
• Compliance: Sensitivity labels or organizational policies may override sharing settings. 

You can refer to the following Microsoft articles about guest access:

• Guest access in Microsoft Teams
• Microsoft 365 guest sharing settings reference
• "Attempted to perform an unauthorized operation" error when accessing Files tab in Teams

6/ Contact Microsoft Support  

If the issue persists after these checks, it may stem from a deeper system-level cause. In this case, I recommend contacting your organization's IT administrator, who can submit a support request to Microsoft through the Microsoft 365 Admin Center. They’ll be able to access system-level information to investigate the issue thoroughly and provide assistance. At the very least, they can offer the most effective workaround to ensure your experience remains smooth and secure.  

We kindly ask for your understanding that, as moderators, we do not have access to the administrative tools or permissions required to investigate or modify these configurations. We also do not have the capability to initiate remote sessions for direct assistance. Our role is to guide users to the appropriate resources and support channels.    

I hope this helps resolve the issue with guest users being unable to share files in Microsoft Teams. I'm glad to assist and truly hope the information provided has been helpful. If you need further support or have any additional questions, please don’t hesitate to reach out. 

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Thank you for your kindness and contributions to the forum. 

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