Massachusetts Late Fee Calculator
Work out interest on an overdue B2B invoice under Massachusetts law. The legal default rate — what applies when the contract is silent — is 6%, and the statute is quoted verbatim below. All math runs locally in your browser.
Default legal rate when there is no agreement or provision of law for a different rate; a higher rate is recoverable in a suit only if the agreement to pay it is in writing. Separately, in contract actions the clerk of the court adds prejudgment interest at the contract rate, if established, or at 12% from the date of breach or demand.
Late fee breakdown
- Interest owed
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- Daily rate
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- Total (invoice + interest)
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Still unpaid? Generate a formal demand letter — it computes the interest and cites Massachusetts's statute (MGL c.231 § 6C; c.107 § 3; c.271 § 49) for you.
What Massachusetts law actually says
If there is no agreement or provision of law for a different rate, the interest of money shall be at the rate of six dollars on each hundred for a year, but, except as provided in sections seventy-eight, ninety, ninety-two, ninety-six and one hundred of chapter one hundred and forty, it shall be lawful to pay, reserve or contract for any rate of interest or discount. No greater rate than that before mentioned shall be recovered in a suit unless the agreement to pay it is in writing.
Quoted verbatim from the linked official source — not our paraphrase. How we source and re-check every row is documented in the data methodology.
Maximum late fee in Massachusetts — written B2B contracts
Hard cap 20% criminal (all-in).
20%/yr criminal-usury ceiling, counting all fees and charges; no blanket business exemption. Exceeding it is lawful only if the lender files notice with the Attorney General.
Basis: MGL c.271 §49; c.107 §3. Compare all 51 jurisdictions on the full state table and the cap-regime map.
B2B invoices only — not rent, not consumer debt
Everything on this page is about business-to-business invoices. Residential rent late fees live in Massachusetts's landlord-tenant law and consumer credit has separate, stricter rules — two different bodies of law. The distinction is explained in B2B invoice late fees vs. residential rent.
Use this data
Massachusetts's row — rate, cap, citation, verbatim quote, verification date — is part of our open 51-jurisdiction dataset: CSV · JSON (CC BY 4.0, cite myinvoicetemplate.com). Set late-fee terms on your next invoice with the free invoice generator, or state them clearly using the wording guidance in the payment terms guide.
Massachusetts late fee FAQ
Can I charge late fees on overdue invoices in Massachusetts?
Yes — on business-to-business invoices. If your contract or invoice states a late-fee rate, that rate governs (subject to the cap rules below). If nothing was agreed: 6%. Default legal rate when there is no agreement or provision of law for a different rate; a higher rate is recoverable in a suit only if the agreement to pay it is in writing. Separately, in contract actions the clerk of the court adds prejudgment interest at the contract rate, if established, or at 12% from the date of breach or demand. Statute: MGL c.231 § 6C; c.107 § 3; c.271 § 49, verified 2026-08-21. Consumer and rent debts follow separate laws.
What is the maximum late fee I can charge in Massachusetts?
For a written B2B contract: 20% criminal-usury ceiling (all-in, including fees) unless the lender notifies the Attorney General; no blanket business exemption. Basis: MGL c.271 §49; c.107 §3. The full cap analysis is in the section above; this covers business-to-business deals only — consumer credit has stricter separate caps.
What interest applies if my contract doesn't mention late fees in Massachusetts?
The statutory default rate of 6%. Default legal rate when there is no agreement or provision of law for a different rate; a higher rate is recoverable in a suit only if the agreement to pay it is in writing. Separately, in contract actions the clerk of the court adds prejudgment interest at the contract rate, if established, or at 12% from the date of breach or demand. Statute: MGL c.231 § 6C; c.107 § 3; c.271 § 49 (verbatim quote on this page, verified 2026-08-21).
Does this cover rent, apartment, or consumer late fees in Massachusetts?
No. This page covers business-to-business invoices only. Residential rent late fees are governed by Massachusetts's landlord-tenant law, and consumer credit for personal, family, or household purposes has its own stricter caps and disclosure rules. Those are different statutes than the commercial-interest law cited here.
Where does this data come from, and when was it verified?
Every figure on this page comes from our 51-jurisdiction dataset: each row researched against the controlling statute or the state's official current-rate page, independently re-checked, and stamped with its own verification date — Massachusetts's row was last verified 2026-08-21. The operative legal text is quoted verbatim on this page with a link to the official source, the methodology is public, every verification pass is logged in the changelog, and the full dataset is downloadable (CC BY 4.0).
Not legal advice. This page summarizes Massachusetts's commercial-interest statute for general information, with the verification date shown above — it tells you when we last confirmed the figures, not that they are still current today. Statutes change and courts interpret them; verify the cited statute at the official source, or ask a licensed attorney in your state, before charging or demanding interest.