Workeey is built for your phone. Scan the code with your phone to get the Android app, or open workeey.com on your phone. The iPhone app and a desktop version are coming soon.

Get the Workeey app. Same account, same jobs.

QR code — scan it with your phone to get Workeey from Google PlayGet it on Google Play
Free data

Interest on unpaid invoices in Idaho: 12% a year if no rate was agreed; no general cap found

By Yossi Grunwald, founder of Workeey · Updated

In Idaho, 12% a year if no rate was agreed; no general cap found. Read from Idaho's own statutes, agencies and courts, checked November 6, 2026, with every answer quoted below, and a late fee calculator.

Start free No card needed · free plan forever

Idaho's rate when no rate was agreed

12% a year. 12% a year when no written contract fixes a different rate; on open accounts it runs after three months from the date of the last item.

The most you can set in Idaho

For homeowners and businesses alike: See the state's words below. Idaho Credit Code § 28-42-201(1), which covers loans and credit sales. § 28-42-201(1) is not limited to consumer transactions, and the act applies to 'sales and loans made in this state' (§ 28-41-201(1)).

  • “With respect to a loan or credit sale, the rate of finance charge shall be that which is agreed upon between the parties to the transaction.” — Idaho Code § 28-42-201(1) Maximum finance charge, read November 6, 2026
  • “Except as otherwise provided in this section, this act applies to sales and loans made in this state and to modifications, including refinancings, consolidations, and deferrals made in this state, of sales and loans, wherever made.” — Idaho Code § 28-41-201(1) Territorial application, read November 6, 2026

Late fees in Idaho

What the text says: Regulated consumer credit transactions: delinquency charge may be contracted for on a payment not paid in full within 10 days of its due date, max the greater of 5% of the unpaid payment or $15 ($12.50 on precomputed transactions). Regulated consumer credit transactions — credit sales of goods or services (incl. work and labor) for a personal, family or household purpose by a seller who regularly extends such credit, where the debt is payable in installments or a finance charge is made; open-end and closed-end.

  • “With respect to all other regulated consumer credit transactions, whether secured or unsecured, and whether such credit transactions are classified as open-end credit or closed-end credit, the parties may contract for a delinquency charge on any installment or scheduled payment not paid in full within ten (10) days after its scheduled due date in an amount not exceeding five percent (5%) of the unpaid amount of the installment or scheduled payment, or fifteen dollars ($15.00), whichever is greater.” — Idaho Code § 28-42-301(3) Delinquency charges, read November 6, 2026
  • “With respect to a precomputed regulated consumer credit transaction, the parties may contract for a delinquency charge on any installment not paid in full within ten (10) days after its due date, as originally scheduled or as deferred, in an amount which is not more than five percent (5%) of the unpaid amount of the installment, or twelve dollars and fifty cents ($12.50), whichever is greater.” — Idaho Code § 28-42-301(1) (precomputed), read November 6, 2026
  • “a sale of goods, services, or an interest in land in which: (a) Credit is granted either pursuant to a seller credit card or by a seller who regularly engages as a seller in credit transactions of the same kind; and (b) The debt is payable in installments or a finance charge is made.” — Idaho Code § 28-41-301(36) "Regulated credit sale", read November 6, 2026

Does Idaho want it agreed in advance?

Agreed in advance: yes, in the cases below. Delinquency charges in regulated consumer credit transactions are ones 'the parties may contract for'; the legal rate applies only 'when there is no express contract in writing fixing a different rate'.

  • “the parties may contract for a delinquency charge on any installment or scheduled payment not paid in full within ten (10) days after its scheduled due date” — Idaho Code § 28-42-301(3), read November 6, 2026

Homeowners and businesses in Idaho

The delinquency-charge limit applies to credit for a 'consumer purpose' (primarily personal, family or household; not where the debtor is an organization); no rate cap either way.

Prompt payment on private construction in Idaho

Not found in our check for Idaho. No private construction prompt-payment interest rate found.

  • “This section is applicable with respect to all contracts entered into on or after July 1, 1990, between owners and original contractors relating to the construction of any private work of improvement.” — Idaho Code § 29-115(1) Construction contracts, read November 6, 2026

Work out a late charge in Idaho

Starts at Idaho's 12%, the rate when none was agreed, not a maximum.

Days since the due date
The rate or fee your terms set

$11.84 late charge

Days late
30
New total
$1,211.84

$1,200.00 × 12% a year × 30 days ÷ 365 = $11.84

Check Idaho's own text

Before you charge: read Idaho Code § 28-22-104(1) Legal rate of interest and the other Idaho 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 Idaho with every state's answer, or with its neighbours just below.

Next door to Idaho

  • Montana: 10% if none agreed, depends by agreement
  • Nevada: floats if none agreed, depends by agreement
  • Oregon: 9% if none agreed, depends by agreement
  • Utah: 10% if none agreed, no general cap found
  • Washington: 12% if none agreed, depends by agreement
  • Wyoming: 7% if none agreed, depends by agreement

Official sources for Idaho

Every state in one file: Excel and CSV downloads

Where our data comes from

Start free Free plan forever · upgrade only if it earns it