Indiana late fee law

8%per year

Attaches to the debt by operation of law when you agreed no rate, so it accrues before any lawsuit and can be stated on a demand letter.

When the parties do not agree on a rate, interest on loans or forbearances of money, goods, or things in action is 8% per annum until payment of judgment. Post-judgment interest is the contract rate up to a maximum of 8%, or 8% absent agreement (Ind. Code § 24-4.6-1-101). Verified against FindLaw/Justia statute text and Indiana appellate case commentary on courts.in.gov; the official iga.in.gov code browser could not be machine-fetched, so text was not confirmed on the legislature site itself.

Parties may contract for a different rate; Indiana's rate caps (Uniform Consumer Credit Code, Ind. Code art. 24-4.5) are directed at consumer credit, and business/commercial-purpose credit is generally outside those caps, so agreed B2B finance charges are enforceable subject to unconscionability and the criminal loansharking statute. Note that post-judgment interest is capped at 8% even if the contract rate is higher (Ind. Code § 24-4.6-1-101). Verify specific transaction structures with counsel.

public

State agencies and political subdivisions must pay a late-payment penalty of 1% per month on amounts due under written public contracts (public works, goods, services) not paid when due (generally within 35 days if no date specified); contractors must pass through 1%/month to subcontractors (Ind. Code § 5-17-5-4). No general prompt-payment act covering ordinary private commercial invoices was found.

No distinctive Indiana statute on flat late fees for commercial invoices was found; default rule applies - an agreed late fee is enforceable if it is a reasonable liquidated-damages provision rather than a penalty. Absent an agreed charge, the 8% statutory rate under § 24-4.6-1-102 is the usual measure of interest on overdue amounts.