What the Prepayment Privileges Ratio Actually Means When you sign paperwork for your mortgage the prepayment privileges will be part of that mortgage. They are usually stated as 15/15, some lenders have products that are 20/20. Sounds like vision right? wrong. The first number is the % by which you can increase your regular payments. The second number is the % of your original mortgage that you can apply lump sum payments each year. Here is an example with actual numbers