If the repair is not finished/closed, there will be no balance owing to the patient's account. Even a $0 repair should be closed by clicking Generate Invoice in the last screen of a repair.
If it is in a closed period the date range can be temporarily opened so that you can adjust prices etc then click on Generate invoice to close it. This does two things, it allows you to adjust the "date of repair" in the Header (which is not the invoice date, it is the actual repair date) and allows you, in the last screen, to click on Generate Invoice which creates an invoice for the repair with whatever date you like, allows payment with today's date as the default.
From late 2019, repairs have been added to the date range control. Setting this will allow users to overwrite the repair date, but the "Generate Invoice" date will be subject to dAte Range control.
CREDIT - Clicking this box will designate that this repair is a Credit Repair. When checking this option, the COST associated with each repair problem will flow through as a credit (negative) amount to your accounting system. If the invoice to the patient should also be a credit, the AMOUNT for each detail line will need to be manually edited to be a credit (negative) amount.