Unpaid invoice? They signed, they owe. Make the demand official.
For small businesses and individuals owed money under a contract, invoice, or agreement. A firm attorney demand stating the debt, the 9% statutory interest running since the due date, and exactly what happens next.
Flat fee $499, signed by a licensed New York attorney, draft within 48 hours, mailed on your approval.
Reviewed by Daniel Hochman, Esq. · Last updated November 1, 2026
Yes. A New York attorney's demand letter for an unpaid invoice states the debt, a deadline and what happens next, and it adds the interest the law allows: 9% a year on contract and commercial claims from the date payment was due (CPLR 5001, 5004), or 2% on a consumer debt owed by an individual. The dated letter is also your record that you demanded payment before suing.
For business and commercial debts of $1,000 and up. If the firm takes your case for collection, the full flat fee can go toward it. Background reading from the firm: B2B commercial collections. Want fewer of these? The firm also writes flat-fee business contracts that put the payment terms in writing before you deliver.
Interest has been running
New York's statutory prejudgment interest on contract and commercial claims is 9% per year from the date payment was due. The longer they stall, the more they owe, and the letter says so. Consumer debts owed by an individual carry a 2% rate instead, and your letter states the correct one.
CPLR 5001, 5004
A documented final chance
The letter creates a clean, timestamped record that you demanded payment before suing, strengthening your position in any court.
Debtors pay counsel, not creditors
An invoice from you is a request. A demand on law firm letterhead is a preview of litigation.
Questions before you start
The debtor is disputing the quality of my work. Will a letter help?
It can. Disputed debts can still be demanded, and the letter frames the dispute on your terms. Heavily contested matters may warrant representation instead; intake review sorts this.
Can I demand my collection costs too?
Yes, if your contract has a fee provision, and the letter will invoke it.
How much interest can I add to an unpaid invoice in New York?
9% a year on contract and commercial claims, running from the date payment was due (CPLR 5001, 5004). A consumer debt owed by an individual carries 2% instead, and the letter states the correct rate.
Do I need a lawyer to send a demand letter for an unpaid invoice?
No, you can send one yourself. A letter on law firm letterhead lands differently, though: an invoice from you is a request, while an attorney's demand with the interest already computed is a preview of litigation.
Statutes cited on this page
CPLR § 5001 (Civil Practice Law and Rules)
Each link opens the official text at the New York State Senate's Open Legislation site (federal sections: Cornell Law School's U.S. Code).