Share via

Can (video) call external users but not those in unmanaged tenants

Vincent Miggels 25 Reputation points
2025-09-19T11:00:20.51+00:00

The call button is greyed out and when I hover it, it says 'Calling isn't available in this chat' when I try to contact users with an unmanaged Teams account. I used to have a M365 license from another company and Teams worked flawless, I have now switched over to my own M365 Business Standard license and for some reason this doesn't work anymore, calling Teams users in a managed Teams account works just fine.

Teams and Skype for Business users in external organizations is set to all domains.

People in my organization can communicate with unmanaged Teams accounts is set to on.

No restrictions in any policies either.

I previously switched these to off, waited, then switched them back on. Sign out and into my Teams many times over. Reinstalled Teams and looked at the settings with an external 'expert' but we just kept going over the same settings.

The admin/app settings seem pretty straight forward, they just appear not to do what they should.

Does anyone have additional suggestions? I have friends that I video called before that I now cannot contact through Teams anymore.

Microsoft Teams | Microsoft Teams for business | Meetings and calls | Other
0 comments
Answer accepted by question author
  1. Rin-L 18,495 Reputation points Microsoft External Staff Moderator
    2025-09-19T13:06:16.0533333+00:00

    Hi @Vincent Miggels, 

    Thank you for posting your question in the Microsoft Q&A forum. 

    After reviewing your detailed description, it looks like you've already configured the correct settings for external access and federation. I understand how frustrating this issue can be, especially since it used to work seamlessly with your previous license. 

    May I ask: Do you experience the same issue when using the Teams web app? If the problem persists across both desktop and web versions, I’m afraid this might require a deeper investigation from the backend. 

    While I’d love to assist you further, due to limited access and tools, I’m unable to directly resolve backend-related issues. I sincerely recommend raising a support ticket via the Microsoft 365 Admin Center by navigating to Support > Help & Support.

    User's image

    The support team there has elevated permissions and access to backend diagnostics, making them better equipped to investigate and resolve this issue efficiently.

    Note: If you are an end- user, please contact your IT admin to follow these steps.   

    For reference:  Get support - Microsoft 365 admin | Microsoft Learn   (Online support)  

    Thank you for your patience and understanding. I hope this gets resolved quickly, and I’m here if you have any further questions. 

    If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

    Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

    1 person found this answer helpful.

1 additional answer

Sort by: Most helpful
Most helpful Newest Oldest
  1. Vincent Miggels 25 Reputation points
    2025-09-22T09:44:30.3666667+00:00

    After raising the support ticket with Microsoft I was contacted 2 days later and the issue was resolved. It's a bit unclear what exactly was done in the background but I was informed that my organization in Microsoft appeared 'dehydrated' and they ran some internal diagnostics on it and that solved the issue, no settings were changed. It was basically a refresh of my installation and that did the trick.

    So to anyone struggling with this kind of issue, contact Microsoft directly.

    1 person found this answer helpful.

Your answer

Answers can be marked as 'Accepted' by the question author and 'Recommended' by moderators, which helps users know the answer solved the author's problem.