If they just want to ""list"" those terms on the invoice, I would add a Text Box to the invoices reflecting the information. Maybe even some fancy calculations that would then Calculate the Net Due, based on those percentages. BUT, what do they do when an invoice is aged 20 days, and the customer took the 15% (that they are not entitled to take)? Seems clumsy and might look like a ""Going out of business sale"". The offer for 20% prepaid or CC is manageable; but the rest... maybe not.