Connecticut late fee and interest rules for invoices

Here is what Connecticut law says about late fees and interest on unpaid invoices, for business clients and consumers, with the statute and a link to the official source.

This is general information, not legal advice. Laws change and can apply differently to your situation, so check your state's current law or ask a lawyer before you charge a late fee, interest or a deposit. Last reviewed October 21, 2026.

Connecticut late fee and interest limits

Rule	Connecticut
Business-to-business late fee or interest cap	When no rate was agreed, a court may award up to 10% a year on a late payment. To be safe, keep an agreed rate at or under 12% a year, in writing.
Consumer cap	No specific limit found for invoices to individuals. Keep the fee reasonable and agreed in writing.
Legal interest rate when no rate was agreed	8% a year. Courts may award up to 10% a year on money held back after it was due.
Statute	Conn. Gen. Stat. §§ 37-1, 37-3a, 37-4
Last reviewed	October 21, 2026

Late fee wording to copy

Agree on the fee before the work starts and show it on every invoice.

Payment is due within 30 days of the invoice date. Balances unpaid after the due date are charged interest of [rate]% per month.
A late fee of $[amount] applies to any balance not paid by the due date.
Past due balances accrue interest at [rate]% per year, or the highest rate allowed by law, whichever is lower.

Keep going

Late fee calculatorWork out the fee or interest on an overdue invoice.How to charge late feesHow to set a late fee and put it on your invoices.Late fee laws by stateEvery state in one table.