Hi Jim, while that sounds a good idea, what happens when that client books again in 6 months time. Their account balance is zero, so you could easily miss the opportunity to charge them what you are rightfully owed.
The best way is to create an expense for the write off amount with the clients name in the notes.
This still leaves the outstanding amount of their account for future reference.
I would like to see from Cliniko a flag that is shown (green and red) with the amount that the client is in or out of credit when you make a booking and choosing the patients name from the drop down. This drop down should also include their date of birth. (if you have more than one client with the same name.