If you are on a call and you decide that you need to have a conference call that includes the person to whom you are speaking and additional participants, this can be done in the Conversation window of the current call. 

Escalating a Call to a Conference Call

To escalate a call to a conference call:

1. During a call, in the Conversation window, click the People options button.

2. In the Invite more people dialog box, enter a Contact or number in the Search

3. Double click the contact’s name OR phone number that appears in the area below the Search

4. Once the call is accepted the invitee will show up on the Attendees list.

How to make a conference call - Microsoft Teams - Windows

For Microsoft Teams related questions or problems, send email to unifiedcommunications@uh.edu.