Here's the information you'll need to have handy to complete your unsecured promissory note, interest-only with balloon final payment. Set loan terms with larger payments at the end.The Texas Real Estate Lien Note is a oneway agreement in which the signer makes a promise to pay someone a specific sum of money at a specific time. All payments shall first be applied to outstanding late fees, then to interest and the balance to the Principal amount. Here's the information you'll need to have handy to complete your secured promissory note, interest-only with balloon final payment. A monthly interest rate can be included on the promissory note.