Do I need a clause in my contract to charge this?

Effectively yes. New York has no automatic statutory right to add interest to a private commercial invoice — your contract or terms of trade should specify the rate. Without one, you are limited to the default legal rate (9% per year) on liquidated debts, typically only recoverable once you pursue the claim.

How is late payment interest calculated?

Simple interest on a daily basis: invoice amount × (annual rate ÷ 365) × days overdue. Interest normally runs from the day after the due date. The calculator above shows the formula with your own numbers.

Can I really send an invoice for the interest?

Yes — the standard practice is a short statement or updated invoice showing the principal, the daily interest accrued to date and the legal basis (N.Y. CPLR §§5001, 5004). Many creditors find the demand itself prompts payment. This site provides information, not legal advice; for significant sums, confirm your position with a professional before escalating.

Late Payment Interest in New York (2026)

9% per year — CPLR §5004: interest at 9% per year on contract claims; CPLR §5001 grants pre-judgment interest on breach of contract as of right, from the date of breach. On a $5,000 invoice 60 days overdue, the money already owed to you looks like this:

Total owed on a $5,000 invoice · 60 days late

$5,073.97

Growing $1.23 every day it stays unpaid

principal: $5,000
interest: $73.97

Rate verified 2026-07-06 · Source: NY Senate — CPLR 5004 · Methodology

Calculate your invoice

Rate prefilled from the New York default (9% per year) — override it if your contract sets its own.

Invoice amount

Due date

60 days overdue

Annual rate

New York default: 9% per year

Total now owed to you · New York

$5,073.97

$5,000 principal · 60 days overdue at 9%

interest accrued: $73.97
growing daily by: $1.23

Simple interest: amount × (9% ÷ 365) × 60 days. Information, not legal advice — contract terms can override statutory defaults.

The rule in plain English

New York is unusually creditor-friendly on paper: pre-judgment interest on a breached contract is a right, not a discretion, and the statutory rate is a flat 9% per year.

For an unpaid invoice, interest at 9% runs from the date the payment became due (the earliest ascertainable date of breach).

The 9% rate is fixed by statute and does not float with market rates — it has been 9% since 1981 (a 2022 amendment lowered it to 2% only for consumer debt judgments; commercial claims remain at 9%).

As always, an explicit contract rate overrides the statutory default, subject to New York usury limits (16% civil / 25% criminal for most non-corporate borrowers).

Legal basis: N.Y. CPLR §§5001, 5004.

Worked example

invoice = $5,000, 60 days overdue, rate = 9.00%

daily interest = $5,000 × (9.00% ÷ 365) = $1.23

interest = $1.23 × 60 days = $73.97

total owed = $5,073.97

What to include in your demand letter

A short, factual letter recovers more invoices than a heated one. Checklist (general guidance, not legal advice):

Invoice number, date, original due date, and the exact principal outstanding.
The interest calculation shown line by line — principal, rate (9% per year), days overdue, daily amount — so there is nothing to dispute.
The legal or contractual basis for the interest (N.Y. CPLR §§5001, 5004; cite your contract clause first if you have one).
A single clear deadline (7 or 14 days is customary) and the payment details — remove every excuse for delay.
What happens next if unpaid: a letter before action, small claims / court filing, or referral to collections — stated plainly, without threats you don’t intend to keep.
A note that interest continues to accrue daily until payment — quote the per-day figure from the calculator above.

FAQ

What interest can I charge on a late invoice in New York?: CPLR §5004: interest at 9% per year on contract claims; CPLR §5001 grants pre-judgment interest on breach of contract as of right, from the date of breach. On a $5,000 invoice 60 days overdue, that is about $73.97 in interest. (N.Y. CPLR §§5001, 5004; verified 2026-07-06.)
Do I need a clause in my contract to charge this?: Effectively yes. New York has no automatic statutory right to add interest to a private commercial invoice — your contract or terms of trade should specify the rate. Without one, you are limited to the default legal rate (9% per year) on liquidated debts, typically only recoverable once you pursue the claim.
How is late payment interest calculated?: Simple interest on a daily basis: invoice amount × (annual rate ÷ 365) × days overdue. Interest normally runs from the day after the due date. The calculator above shows the formula with your own numbers.
Can I really send an invoice for the interest?: Yes — the standard practice is a short statement or updated invoice showing the principal, the daily interest accrued to date and the legal basis (N.Y. CPLR §§5001, 5004). Many creditors find the demand itself prompts payment. This site provides information, not legal advice; for significant sums, confirm your position with a professional before escalating.

This page is general information about New York, verified 2026-07-06 against NY Senate — CPLR 5004. It is not legal advice, and statutory rules have exceptions and transition rules that a short summary cannot capture. Contract terms often override statutory defaults. For significant or disputed sums, consult a qualified professional in your jurisdiction.

Other jurisdictions

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