So that future appts don't have a deposit. This is confusing to the staff and client. It should be that the deposit (and only that portion) for a particular service is FORCED to be used for the particular service that created it. Lapsed appts with deposits should have option of automatic redemption of it.

For example if a service is $10 and deposit is 50% but client has 4 repeating appointments of it. Checkout of 1st appt will show ACCT BAL of $20, client will pay, staff will use ACCT BAL and potentially even tip from the balance... Expected behavior is use $5 from ACCT BAL and then rest and tip are due at checkout.

Would also be great if deposits were not collected at booking time, that it is commitment to transaction. Then at checkout, either normal checkout as one whole transaction amount. If appt missed, then auto-transact the deposit amount from appt while removing appt time to allow for other bookings.

Lastly, behavior of deposits potentially cause double transaction merchant fees because broken into two. This is harmful to the business.