How do I use a promissory note to secure an overdue invoice?
How to use a promissory note to secure an overdue invoice
Short answer
A promissory note converts a disputed or overdue invoice into a signed, standalone acknowledgment of debt — which is harder to dispute, may extend the statute of limitations, and can be sold or assigned more easily than an open invoice. Use it when a customer acknowledges they owe the money but cannot pay immediately and you want the obligation formalized before agreeing to a payment plan.
An open invoice is a record of a commercial transaction. A promissory note is a signed promise to pay a specific amount by a specific date or schedule, with or without interest. Converting an overdue invoice into a note changes the legal instrument. The debtor has now affirmatively signed an acknowledgment of the debt, which makes "I never agreed to that" much harder later. It also typically resets the statute of limitations from the date the note is signed instead of running from the original invoice date.
The mechanics are simple. Both parties agree on the outstanding balance, a payment schedule, and optionally an interest rate. You draft a written promissory note with those terms, the debtor signs it, and the note references the original invoices it satisfies. Once signed, the note is the governing document. If they default, you pursue them under the note rather than the original invoice.
Notes are most useful in two situations. One is a customer who has fallen significantly behind but is acting in good faith and wants a structured plan. The other is when you're worried about the statute of limitations on an older invoice and want to reset the clock with a new signed instrument. With evasive or disputing customers, you're unlikely to get a signature anyway. Notes only work when both parties agree on the amount owed.
Don't confuse a promissory note with a payment plan agreement. They serve similar purposes, but a note is a negotiable instrument with specific legal characteristics. In some states, notes can be transferred to third parties, used as collateral, or enforced through a summary process separate from full civil litigation. For larger overdue balances, paying an attorney to draft the note is worth it to make sure it's enforceable in your jurisdiction. Not legal advice.