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.Written notice to the Trustor, or his successor in interest, of prescribed information at least 90 and not more than 150 days before any balloon payment is due. This document is a secured promissory note between a borrower and payee.