Legal

Idaho prompt payment act and retainage rules

Idaho state agencies and taxing districts must pay bills within 60 calendar days or owe interest. Retainage is capped at 5% on bonded public jobs (released 30 days after acceptance) and on most private jobs (reduced and released within 35 days of substantial and final completion).

An office manager and contractor review invoices with a calculator and laptop in a construction office.
Review invoices, committed costs, and cash timing together before making project decisions. AI-generated illustration.

Idaho spreads its payment rules across three statutes. Idaho Code 67-2302 makes the state and every taxing district pay bills within 60 calendar days of receipt, with interest added automatically when they are late. Idaho Code 54-1926 caps retainage at 5% on bonded public works and requires release within 30 days after acceptance. On private work, Idaho Code 29-115 caps retention at 5%, requires it to be cut down within 35 days of substantial completion and released within 35 days of final completion, and gives subs 10 days to receive their share once the GC is paid.

Idaho payment and retainage rules at a glance
RulePublic workPrivate work
Owner pays primeWithin 60 calendar days of receiving the bill, unless the contract allows longer (67-2302)Set by contract; no statutory progress payment deadline
Interest on late paymentAutomatic; rate set in Idaho Code 63-3045; compounds monthlyNot set by 29-115
Retainage cap5% when bonds over 50% of the contract are required (54-1926)5% of each payment and of the contract price (29-115)
Retainage from subs5% maximum5% maximum
Release to primeWithin 30 days after the public body and contractor accept a portion of the project as completeReduced within 35 days of substantial completion; released within 35 days of final completion
Release to subsWithin 30 days after the subcontract is completeWithin 10 days after the GC receives retention
Interest on retained fundsStarts 30 calendar days after the contractor completes work, unless the contract says otherwise (67-2302)Not set by 29-115
WaiverNot addressedRequiring a waiver of 29-115 is against public policy

Public work: the 60-day rule

Section 67-2302 states that all bills owed by the state of Idaho or any taxing district shall be paid promptly, and it expressly applies to construction, repairs and remodeling. Bills must be accepted, certified and paid within 60 calendar days of receipt unless the buyer and vendor agreed in the contract to a longer period. Payment is due from the later of the date the agency officially receives the invoice or the date it receives the goods or services.

  • Interest is automatic when bills go overdue, unless the contract spells out its own late-payment terms. The contractor calculates the interest and invoices it with the principal.
  • Rate: the rate in Idaho Code 63-3045, compounding monthly on unpaid interest.
  • Bad invoices: the agency must contact you in writing within 10 days if an invoice is defective. Fix it within 5 working days and the payment is not treated as late.
  • Retained amounts: interest on retainage begins 30 calendar days after the contractor completes the work, unless the contract provides otherwise.
  • Disputes: interest may be postponed during a disagreement, but at resolution the contractor gets interest on all proper invoices.
  • Fees: if a vendor brings an action to collect interest and prevails, the agency pays reasonable attorney fees awarded.

Public work: bonds and retainage under 54-1926

For public contracts of $50,000 or more, the contractor must furnish a performance bond and a payment bond, each at least 85% of the contract amount. When a public body requires a bond over 50% of the contract, it may not hold more than 5% of the total amount payable as retainage. It must release retainage on portions of the project accepted as complete within 30 days after acceptance.

The cap flows down. A GC on a public job may not hold more than 5% from a sub and must remit the sub's retainage within 30 days after the subcontract is complete. Say a site concrete sub finishes $300,000 of work on a school in month four of a 14-month job. The GC can hold at most $15,000, and that money is due 30 days after the concrete scope is done, not after the building is.

Private work: Idaho Code 29-115

Section 29-115 covers contracts for private works of improvement entered on or after July 1, 1990. Retention by the owner from the GC, or by the GC from a sub, cannot exceed 5% of any payment or 5% of the contract price in total. Two exceptions: the cap does not apply if a contractor or sub fails to provide a performance bond when asked, and it does not apply to owner-occupied homes of one to four units.

  • Substantial completion: within 35 days, retention drops to the lesser of 150% of the estimated value of remaining work or the amount being held, never over 5% of the contract price.
  • Final completion: within 35 days, retention is released. In a dispute the owner may keep up to 150% of the estimated value of the disputed issue, and may require lien waivers from everyone with actual or potential lien claims.
  • Pass-through: within 10 days after the GC receives any retention, it pays each sub its share. Retention designated for a specific sub goes to that sub.
  • Sub disputes: with a bona fide dispute, the GC may hold up to 150% of the value of the remaining work or disputed issue.

Section 29-115 also says private construction contracts in Idaho are subject to Idaho law and cannot require litigation, arbitration, or other dispute resolution in another state or country. Requiring any party to waive the section is against public policy.

Tracking it on real jobs

Two clocks (30 days public, 35 days private) and a 10-day pass-through are easy to miss when closeout drags. Log the substantial and final completion dates, the acceptance date on public work, and the day each retention check lands. Also check Idaho contractor registration and Idaho prevailing wage rules, and read our prompt payment act primer. Smart Business Automator tracks retainage held and billed on every job and subcontract; see construction accounts receivable automation.

Frequently asked questions

How long does an Idaho public agency have to pay a contractor?

Under Idaho Code 67-2302, bills must be paid within 60 calendar days of receipt unless the contract in place when the order was placed allows a longer period. Late bills accrue interest automatically.

What is the retainage limit on Idaho public works?

When the public body requires a performance or payment bond over 50% of the contract, retainage cannot exceed 5% of the total amount payable. The same 5% cap applies from GC to sub.

Does Idaho limit retainage on private projects?

Yes. Idaho Code 29-115 caps retention at 5% on private works, except when a requested performance bond is not provided and on owner-occupied homes of one to four units.

When must a GC pay subs their retainage on a private Idaho job?

Within 10 days after the GC receives all or part of the retention, unless a bona fide dispute exists with that sub.

Can a private contract waive Idaho's retention rules?

No. Section 29-115 says it is against public policy for any party to require another to waive any provision of the statute.

Sources

  1. Idaho Legislature: Idaho Code 67-2302, prompt payment for goods and services
  2. Idaho Legislature: Idaho Code 54-1926, public works bonds and retainage
  3. Idaho Legislature: Idaho Code 29-115, private construction contracts

Laws and rates change. Confirm current requirements with the state agency before you bid, file, or pay. This page is general information, not legal advice.

Written and edited by

Maurice Francois writes and edits construction operations guides for Smart Business Automator. More from Maurice on the Scaling Legends podcast.

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