Here's the information you'll need to have handy to complete your unsecured promissory note, interest-only with balloon final payment. Here's the information you'll need to have handy to complete your secured promissory note, interest-only with balloon final payment.This form is perfect for anyone looking to create a legally binding document for a loan with a balloon payment structure. A single final balloon payment for the entire outstanding Principal amount and interest accrued will be paid on or before the day of. All you need to know about promissory notes. Use our builder or a free customizable template for home, car, or business Loan. This appeal arises from a suit on a promissory note that contained a balloon payment.