Your diary is a central part of your business and records the work carried out and the clients you have. For that reason TM2 allows you to bill directly from the diary, in many cases with a single key press.
Within TM2 you set up your appointment charges and allocate these to practitioners or patient groups ( such as charges for insurance companies etc.). When you create an appointment TM2 works out the charge for that patient at that time. You can of course change this, but with a well configured system, TM2 does the thinking for you.
When you tell the system that the appointment has been completed, TM2 bills for it. This could be to the patient, to a company, for invoicing immediately or for invoicing later - all of this is pre-configured, so TM2 knows what to do and all you have to do is check and click.