Same Sharing Experience Used Across Microsoft 365
Microsoft originally announced that Teams would gain a new file sharing experience in Office 365 notification MC218732 on 16 July 2020 (Microsoft 365 roadmap item 51230). As is sometimes the case, the roll-out was delayed:
Update (September 3): Microsoft report that they have paused the roll-out of the feature to make some additional code changes. They will issue a further update when the roll-out resumes.
Update (February 18): Microsoft is ready to restart the roll-out in mid-March with the goal of completing it by mid-April.
Referring to the update as a new file sharing experience is a stretch. What’s really happening is that Teams is adopting the common file sharing dialog that’s already used in OneDrive for Business, SharePoint Online, and OWA. It’s part of an effort to achieve consistency in sharing behavior across Office 365 announced at the Microsoft Ignite 2019 conference.
In other words, Teams now generates a sharing link when users share files. The sharing link defines who can access the file and what level of access they have to the file (read-only or edit). Teams respects the SharePoint sharing policy for the organization, which dictates the range of sharing links that can be used in an Office 365 tenant. Settings for individual sites can downgrade sharing to a more restrictive level.
Sharing in a Channel
Sharing files in Teams differs between channel conversations and personal chats. When a team member uploads a file to a channel, all team members automatically have access to the file, which is stored in the folder for the channel in the team’s SharePoint document library. There’s usually no need to edit the permissions on a file shared within a channel. You can use a private channel if you want to restrict access to a specific subset of team members and upload the files to that channel.
Alternatively, you can apply a sensitivity label with encryption to confidential information to restrict access to people with the right to view the content. This is sometimes done to restrict access to specific information to the tenant members of a team where guest members are present. Remember that even though guests won’t be able to access the content of protected documents, they’ll be able to see document metadata such as titles.
Sharing in a Chat
When a chat participant uploads a file, the file is stored in the Microsoft Teams Chat Files folder in their OneDrive for Business account and view-only access is granted to the chat participants. People who join the chat later aren’t included in the sharing link and you need to add them to the list of people with permissions (Figure 1).
It’s easy to open the file in OneDrive for Business and amend its sharing permissions to add new chat participants (Figure 2).
However, if you know that multiple people will join a chat in the future and you want them to have access to the files shared in the chat, you can amend the sharing link before posting the file. In Figure 3 we see that the link chosen allows access to everyone in the tenant. This might be appropriate in some situations, but most commonly you’ll probably want to add specific people to the link, especially if some guest users or federated users in other tenants are included in the chat.
Sorry – No Access
When Teams uploads a file to a chat, it evaluates if the participants will be able to access the file in OneDrive for Business. It’s unlikely that you will see this when sharing files in chats with other tenant users, but it can happen when chatting with people from other tenants. To solve the problem, edit the sharing link for the file to ensure that the person has access before completing the upload (or adjust sharing in OneDrive for Business afterwards).
When sharing a file in a personal chat, you’ll be reminded that people who join the chat afterwards will need permission to access shared files. You will need to select each file and update the sharing link to add the new chat participant (this can also be done in OneDrive for Business).
I’ve also seen some reports that the attach file icon is not shown in some chats, usually those with federated users in other Office 365 tenants. If this happens, try opening the chat in a separate window as the icon seems to be available on a consistent basis there. Because Teams now uses the Office 365 sharing model, if you share a document in a chat with a federated user, Teams creates a new Azure AD guest account for that person, which is then used to access the document. A bug appears to stop the new guest account opening the document from Teams, but if they copy the link it will work in SharePoint Online. Chasing down bugs is common when new mechanisms are introduced, and I am sure that Microsoft will fix this problem soon.
Consistency Across Microsoft 365
Support for sharing links inside Teams means that Microsoft 365 now has a consistent approach to file sharing across its major apps. Like OWA, Teams adjusts the sharing model to meet its needs, but it’s still the same mechanism underneath.
Need to know more about how Office 365 sharing works? It’s all explained in chapter 8 of the Office 365 for IT Pros eBook.