Here's the information you'll need to have handy to complete your unsecured promissory note, interest-only with balloon final payment: The first payment will be due on Enter First Payment Date.All payments shall be first applied to interest and the balance to principal. The note doesn't require collateral, and the balloon payment gives your business time to grow before having to make a substantial repayment. The Arizona Unsecured promissory note is a legal document that establishes the various terms of a loan. 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. All prepayments shall first be applied to outstanding late fees, then to accrued interest and thereafter to the principal loan amount. Financial Aid Forms.