The short answer to how you unconfirm a session is that you do not unconfirm sessions.
Why can I not unconfirm a session?
Confirming a session is indicating to Therabill that the session is now part of your Accounts Receivable. In Therabill, all sessions should either be confirmed or deleted. It is best to confirm all sessions as close as possible to the date of service of the session, since sessions that have a date of service in the past should either be deleted or confirmed. If you find that you are wanting to unconfirm a session, then you may want to consider what you are actually wanting to do with the session. Here are some common scenarios.
The session was cancelled
You should be using session classes to cancel your sessions. Even cancelled sessions should be confirmed (to put it in to your A/R).
I don't want to bill the session to the patient
You can either use session classes to mark the session as client not billable, or change the charge amount on it to zero. These types of sessions should also be confirmed.
The session should not be in my calendar
In this case, you will want to delete the session. For information on how to delete a session, please see: How to delete a session.
The session did not take place on the date of service indicated on the session.
In this case, you would want to edit the session to change the date of service. If you change the date of service to the future, then the session will no longer be confirmed.
But, I really, really want to unconfirm the session.
Okay, while un-confirming a session is not something that Therabill recommends or has an easy to use function that will allow you to un-confirm a session, there is a way to do it. Notice in the scenarios above, that if you change the date of service to the future, then session will become unconfirmed (as all future dates of service are unconfirmed). So, you could edit the session to a future date of service and then edit the date back to the correct date of service. The end result would be an unconfirmed session.
Be careful though...
If you already billed out the date of service, you will then have an unconfirmed session that has already been billed out to insurance. This will result in some possible confusion when dealing with the session at a later time.