Interest on unpaid invoices in Indiana: 8% a year if no rate was agreed; the most you can set depends on the deal

Indiana's rate when no rate was agreed

8% a year. 8% a year when the parties do not agree on a rate; from the date of settlement on a written instrument with no rate, and from the date an itemized bill was rendered and payment demanded on an account stated or closed.

• “When the parties do not agree on the rate, interest on loans or forbearances of money, goods or things in action shall be at the rate of eight percent (8%) per annum until payment of judgment.” — IC 24-4.6-1-102, read November 6, 2026
• “(b) And from the date an itemized bill shall have been rendered and payment demanded on an account stated, account closed or for money had and received for the use of another and retained without the other person's consent.” — IC 24-4.6-1-103(b), read November 6, 2026

The most you can set in Indiana

For a homeowner: See the state's words below. The cap is for a consumer credit sale: a seller may contract for and receive a credit service charge not exceeding that permitted by IC 37-2-3-4.

For a business customer: It depends: see IC 24-4.6-1. The parties may agree upon any method of computing interest if the interest does not exceed any limitation imposed by law (IC 24-4.6-1-104(a)).

• “(A) thirty-six percent (36%) per year on that part of the unpaid balances of the amount financed which is two thousand dollars ($2,000) or less;(B) twenty-one percent (21%) per year on that part of the unpaid balances of the amount financed which is more than two thousand dollars ($2,000) but does not exceed four thousand dollars ($4,000); and(C) fifteen percent (15%) per year on that part of the unpaid balances of the amount financed which is more than four thousand dollars ($4,000); or(2) twenty-five percent (25%) per year on the unpaid balances of the amount financed.” — IC 37-2-3-4(b), read November 6, 2026
• “This article must be construed as a recodification of prior law. The enactment of this article by SEA 169-2026 does not affect the substantive operation and effect of the prior law.” — IC 37-2-1-0.1, read November 6, 2026
• “The parties may agree upon any method of computing interest on a loan or a forbearance of money, goods, or things in action if the amount of interest on the unpaid balances of the principal does not exceed any limitation imposed by law” — IC 24-4.6-1-104(a), read November 6, 2026

Late fees in Indiana

What the text says: Once per installment (revolving accounts: each month the minimum is not paid). The $25 is on an installment or minimum payment not paid in full not later than ten (10) days after its scheduled due date.

• “(B) Twenty-five dollars ($25) on any installment or minimum payment due that is not paid in full not later than ten (10) days after its scheduled due date, if installments under the consumer credit sale, refinancing, or consolidation are due every fifteen (15) days or more.” — IC 37-2-3-6(a)(2), read November 6, 2026
• “(C) Twenty-five dollars ($25) on any installment or minimum payment due that is not paid in full not later than ten (10) days after its scheduled due date, in the case of a consumer credit sale, refinancing, or consolidation that is payable in a single installment that is due at least thirty (30) days after the consumer credit sale, refinancing, or consolidation is made.” — IC 37-2-3-6(a)(2), read November 6, 2026
• “A delinquency charge under this section may be collected only once on an installment however long it remains in default.” — IC 37-2-3-6(b), read November 6, 2026

Does Indiana want it agreed in advance?

Agreed in advance: yes, in the cases below. Consumer credit sales: the delinquency charge exists only if 'the parties may contract for' it. Without an agreed rate, the 8% legal rate applies from the date an itemized bill was rendered and payment demanded (IC 24-4.6-1-103).

• “With respect to a consumer credit sale, refinancing, or consolidation, the parties may contract for a delinquency charge of not more than the following:” — IC 37-2-3-6(a), read November 6, 2026

Homeowners and businesses in Indiana

Consumer credit sales (a seller extending credit to a consumer) are capped by IC 37-2-3-4 and the IC 37-2-3-6 delinquency charges.

• “with respect to a consumer credit sale, a seller may contract for and receive a credit service charge not exceeding that permitted by this section.” — IC 37-2-3-4(a), read November 6, 2026

Prompt payment on private construction in Indiana

Not found in our check for Indiana.

Work out a late charge in Indiana

Starts at Indiana's 8%, the rate when none was agreed, not a maximum.

What was not checked for Indiana

• Indiana's criminal loansharking limit (IC 35-45-7), which could cap a business rate, was not read.

Check Indiana's own text

Before you charge: read IC 24-4.6-1-102 and the other Indiana texts quoted on this page, or ask a lawyer. As of November 6, 2026.

This is a plain-words summary of each state's own laws as of November 6, 2026, not legal advice. Rules have exceptions. Check the state's own text, linked on every state's page, or a lawyer before you charge a late fee or interest.

Compare Indiana with every state's answer, or with its neighbours just below.

Next door to Indiana

• Illinois: 5% if none agreed, 9% for homes
• Kentucky: 8% if none agreed, depends by agreement
• Michigan: 5% if none agreed, depends by agreement
• Ohio: floats if none agreed, 8% for homes

Official sources for Indiana

• IC 24-4.6-1-102 — read November 6, 2026
• IC 37-2-3-4(b) — read November 6, 2026

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