How are people usually tracking things if they want to invoice for customer deposits? E.g. customer has an order for $100,000. 30% is due upfront, and but must be recorded as a liability until final payment is complete (and we'd like to use the automatic deposit application to relieve this liability, so we can't just do multiple bills/billing schedules). But that 30% is due with Net 30 terms, and so we need to keep track of the AP associated with this deposit to make sure that the customer actually did pay the 30% or not.