Teams Add New Members – You Are Not Authorised

Using Teams and trying to add External contacts as members of a team? Lets see what happens.

Open the menu to a team and click on Add members.

Lets try and add an external contact as a member by entering their email address and clicking Add.

We get an error message saying we couldn’t add member and you are not authorised.

If you add a user within the tenant it works fine, what’s going on?

The issue here is that only contacts who have an Office 365 tenant associated with their email address can be added as members of a team site. Basically the external contact must be using Office 365! Not even a Microsoft live account can be used, it must be an Office 365 account.

Hope this clarifies the issue for you! and it would be nice if Office eventually let us add non 365 accounts but that’s unlikely to happen any time soon if at all.


Author: Ian@SlashAdmin

Share This Post On
468 ad


  1. Hi Roland,

    Interesting work around! I’m verifying this now but sounds hopeful.

    Post a Reply
  2. Hi Roland,

    I couldn’t make this work. I created a guest user in Azure AD, enabled guest users in teams and assigned the guest user to the team but the portals just don’t recognise the username.

    I even tried using the guest username ianwaters2004_gmail.com#EXT#@Office365LabA.onmicrosoft.com which lets the user log in but teams denies the user access.

    If anyone can offer further advice on this that would be very helpful, even a guide I can re-post here would be great.

    Post a Reply
  3. Login to portal.azure.com > Azure Active Directory > Users – User settings > External collaboration settings
    and play with the option: “Admins and users in the guest inviter role can invite”

    Post a Reply
  4. Hello Ian,

    Dit you get an answer to this problem?

    Post a Reply
    • Hi Peter,

      Not using the suggested fix no.

      Post a Reply

Submit a Comment

Your email address will not be published.