Can I give an external user access to log in to our Teams and use chat?

[Steve Whitcher]

We have a class of user who is an employee of a 3rd party but works in our org in a role similar to some of our employees.  They use a computer provided by their employer, and log in to that employer's domain.  We don't need to create an AD / AAD account for them in our org for any reason, except that we want them to have access to Teams chat.  

How can I allow them to log in to Teams for our tenant using their external email account, allowing them access to Chat with users in our org and to any Teams that we add them to? 

[#2]

Hello @Steve Whitcher   Please see these online references for instructions on how to add a guest to your tenant:

https://docs.microsoft.com/en-us/microsoftteams/add-guests

https://docs.microsoft.com/en-us/microsoftteams/manage-guests

[#3]

Thank you. I didn't know if Guest access allowed users to use Chat functionality outside of a Team. So if I add a guest to azuread but do not add them to any teams, would they still be able to use Teams for 1:1 instant messaging with our staff?

[#4 · Accepted solution]

@Steve Whitcher No, the guest account must be a member of at least one Team. Imagine if some users should only access a file or SharePoint site and if all of them could chat to each other :)

[#5]

@Steve Whitcher 

As others stated, the guest needs to be invited to at least one Team. After that, they will be able to chat with other members (or guests) of that Team using the Chat function, but they will not (in my experience) be able to Chat with other users.

[#6]

That's too bad. We use a lot more 1:1 chat than we do Teams conversations, and that's really what we need these non-staff users to have. Is there no way to do that without creating a user account for them in our domain?

[#7]

@Steve Whitcher AFAIK not for guest users, they must be member of any Team to chat with other users within your organization. Another option would be to enable federation, then you can chat with external users that are using Teams and Skype for Business / Skype Personal without adding them to your tenant. These are the only options I'm aware off.

[#8]

I'm no licensing expert, but maybe you could assign them a Teams license? Or, if they are from a specific domain (e.g.: gmail.com), you could set up federated authentication. Again, I'm no expert on that, so I can't tell you how to do it. This page may help: https://docs.microsoft.com/en-us/microsoftteams/manage-external-access

[#9]

@Dominik Hoefling Just to be clear, if I had to add the guest to a team to get them access to chat, that wouldn't be a big deal.  Based on what @Chad_V_Kealey said though, even if the user is a member of a Team they don't have access to the chat with other users in our organization.  If that's the case, it sounds like adding these users as guests isn't going to work for me.  

Thanks!

[#10]

@Steve Whitcher that's not true actually. As a consultant, I'm a guest in almost 10 tenants and as long as I'm a member of any Team, I can chat with every user in that specific organization, independent which members are in a specific team.

You can easily test it: add your personal account to a Team, switch to your organizations tenant and then try to chat with your organizational account - it will work.