What's included in a Texas Promissory Note? The financial aid office at your college or career school will tell you how you need to complete and sign your MPN.How to complete a Master Promissory Note (MPN): Step 1: Have the following information with you: Verified FSA ID and password. How long will it take? Most people complete each MPN in less than 30 minutes. A promissory note is a legal instrument that establishes a borrower's obligation to repay a specific amount to a lender. Does someone owe you money? Learn how to write a legally enforceable promissary note with our handy, step-by-step guide. You can complete an MPN at any time. Outline the terms and conditions of your loan in Texas.