A monthly interest rate can be included on the promissory note. If the promissory note is an installment or balloon note, this section will detail the amount of each payment or the final lump sum due, respectively.Here's the information you'll need to have handy to complete your unsecured promissory note, interest-only with balloon final payment. These templates simplify the process, providing a structured format that covers all necessary details, from repayment terms to interest rates. Set loan terms with larger payments at the end. Installment Payments with a Final Balloon Payment : These are used mostly in mortgage loans. Here's the information you'll need to have handy to complete your secured promissory note, interest-only with balloon final payment.