Hi @James James
According to your description, we need more information from you to understand the situation and be able to provide you with relevant advice.
- Could you confirm that both your Business Basic account and the recipient's account are properly licensed for Microsoft Teams? To check this admin can log in to the Microsoft 365 admin center --> select Active Users under Users --> find your user --> Apps & Licenses tab, go down and make sure the Microsoft Teams checkbox is checked or enabled.
- Could you confirm that "Allow anonymous users to join meetings" is enabled in your conferencing policy? To check this, go to the Microsoft Teams admin center and navigate to Meetings --> Meeting Policies > Global (Org-wide Default). Make sure "Anonymous users join meetings" is turned on. Teams Settings and Policy Reference - Microsoft Teams | Microsoft Learn.
- Could you confirm that Guest Access is turned on? Refer to External participants (users) are blocked from joining Teams meetings - Microsoft Teams | Microsoft Learn.
- Could you tell if this is happening for all recipients or just a specific recipient? Have you tried asking others in your organization to invite these clients?
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.