Here's a short list of what you'll want to include: Facts of the case. An outline of what happened. Statement of the issue. A brief description of the problem. Demand. The dollar amount or action necessary to resolve the case. Response deadline. The date by which the recipient must respond. Noncompliance consequences.
A simple promissory note might be for a lump sum repayment on a certain date. For example, let's say you lend your friend $1,000 and he agrees to repay you by December 1st. The full amount is due on that date, and there is no payment schedule involved.