Let's say you're working on a project for $1,000.00 and your client's paid the deposit for $500.00, and has opted into auto-pay the remaining $500.00 before your event.
If you added an item for $100.00, thus making the remaining balance $600.00.
Your client will be charged up to their pre-authorized $500.00 prior to your event. The additional $100.00 will need to be paid outside of the auto-payment.