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

Colorado's rate when no rate was agreed

8% a year. 8% a year, compounded annually, when there is no agreement on a rate (C.R.S. § 5-12-101); runs on money due on account from the date it became due (§ 5-12-102(2)).

• “5-12-101. Legal rate of interest. If there is no agreement or provision of law for a different rate, the interest on money shall be at the rate of eight percent per annum, compounded annually.” — C.R.S. § 5-12-101, read November 6, 2026
• “(2) When there is no agreement as to the rate thereof, creditors shall be allowed to receive interest at the rate of eight percent per annum compounded annually for all moneys after they become due on any bill, bond, promissory note, or other instrument of writing, or money due on mutual settlement of accounts from the date of such settlement and on money due on account from the date when the same became due.” — C.R.S. § 5-12-102(2), read November 6, 2026

The most you can set in Colorado

For a homeowner: See the state's words below.

For a business customer: 45% a year. Written instruments may stipulate more than 8% but not over 45% a year, except as otherwise provided in articles 1 to 6 of title 5 (the UCCC).

• “(2) With respect to a supervised loan or a consumer credit sale, except for a loan or sale pursuant to a revolving account, a supervised lender or seller may contract for and receive a finance charge, calculated according to the actuarial method, not exceeding the equivalent of the greater of either of the following:” — C.R.S. § 5-2-201(2), read November 6, 2026
• “(b) Twenty-one percent per year on the unpaid balances of the amount financed.” — C.R.S. § 5-2-201(2)(b), read November 6, 2026
• “(11) (a) "Consumer credit sale" means, except as provided in paragraph (b) of this subsection (11), a sale of goods, services, a mobile home, or an interest in land in which:” — C.R.S. § 5-1-301(11)(a), read November 6, 2026
• “The parties to any bond, bill, promissory note, or other instrument of writing may stipulate therein for the payment of a greater or higher rate of interest than eight percent per annum, but not exceeding forty-five percent per annum, and any such stipulation may be enforced in any court of competent jurisdiction in the state, except as otherwise provided in articles 1 to 6 of this title.” — C.R.S. § 5-12-103(1), read November 6, 2026

Late fees in Colorado

What the text says: Consumer credit transactions (UCCC): the parties may contract for a delinquency charge on an installment not paid in full within 10 days after its due date, up to $15 (not secured by land) or 5% of the unpaid installment (secured by land). Consumer credit transactions — consumer credit sales (installment or finance-charge sales of goods/services to individuals for household use) and consumer loans/leases. It depends: see C.R.S. § 5-1-301(11)–(12).

• “(1) With respect to a consumer credit transaction, the parties may contract for a delinquency charge on any installment or minimum payment not paid in full within ten days after its scheduled due date in an amount not exceeding: (a) Fifteen dollars for a transaction not secured by an interest in land;” — C.R.S. § 5-2-203(1), read November 6, 2026
• “(b) Five percent of the unpaid amount of the installment or minimum payment due for a transaction secured by an interest in land.” — C.R.S. § 5-2-203(1)(b), read November 6, 2026
• “(12) "Consumer credit transaction" means a consumer credit sale or consumer loan, or a refinancing or consolidation thereof, or a consumer lease.” — C.R.S. § 5-1-301(12), read November 6, 2026

Does Colorado want it agreed in advance?

Agreed in advance: yes, in the cases below. A UCCC delinquency charge exists only if 'the parties may contract for' it (C.R.S. § 5-2-203(1)).

• “the parties may contract for a delinquency charge on any installment or minimum payment not paid in full within ten days after its scheduled due date” — C.R.S. § 5-2-203(1), read November 6, 2026

Homeowners and businesses in Colorado

Colorado's own words on it are below.

• “(II) The buyer is a person other than an organization; (III) The goods, services, mobile home, or interest in land are purchased primarily for a personal, family, or household purpose;” — C.R.S. § 5-1-301(11)(a)(II)–(III), read November 6, 2026

Prompt payment on private construction in Colorado

Not found in our check for Colorado. C.R.S. title 24, article 91 (partial payments, retainage) applies to contracts awarded by a public entity.

• “24-91-103. Public entity - contracts - partial payments. (1) (a) A public entity awarding a contract exceeding one hundred fifty thousand dollars for the construction, alteration, or repair of any highway, public building, public work, or public improvement, structure, or system,” — C.R.S. § 24-91-103(1)(a), read November 6, 2026

Work out a late charge in Colorado

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

What was not checked for Colorado

• The Colorado text read is the legislature's 2024 printout of the statutes; changes made in 2025 or 2026, if any, were not checked.
• Colorado's lien and trust-fund laws (title 38) were not searched for a prompt-payment rule on private construction.

Check Colorado's own text

Before you charge: read C.R.S. § 5-12-101 and the other Colorado 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 Colorado with every state's answer, or with its neighbours just below.

Next door to Colorado

• Kansas: 10% if none agreed, depends by agreement
• Nebraska: 12% if none agreed, 16% for homes (two answers)
• New Mexico: up to 15% if none agreed, depends by agreement
• Oklahoma: 6% if none agreed, depends by agreement
• Utah: 10% if none agreed, no general cap found
• Wyoming: 7% if none agreed, depends by agreement

Official sources for Colorado

• C.R.S. § 5-12-101 — read November 6, 2026
• C.R.S. § 24-91-103(1)(a) — read November 6, 2026

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