Here's the information you'll need to have handy to complete your unsecured promissory note, interest-only with balloon final payment. A Promissory Note with Balloon Payments is a loan contract that enables a lender set loan terms with one or more larger payments at the end.Unsecured loans with balloon payments usually have a higher interest rate than conventional loans. The Unsecured Promissory Note Template contains a sample unsecured promissory note that can be customized to document a loan to you. A balloon promissory note has all the usual repayment requirement details, with one important distinction. 1. Enter the borrower's name and contact information.