Prompt payment statutes are laws that require the payment of contractors and subcontractors within a certain period of time, and prescribe interest and penalties for late payments. In some states these laws only apply to public works construction projects that are funded by the government—and sometimes only to public works projects over a certain dollar amount. There is also a federal Prompt Payment Act for federal construction projects.

In Montana, prompt payment statutes are designed to ensure that contractors and subcontractors are paid in a timely manner for their work on construction projects. These laws apply to both public and private construction projects. Under Montana Code Annotated § 18-2-501 et seq., for public works construction projects, state agencies are required to pay contractors within 30 days after receipt of an invoice or after delivery and acceptance of the construction work, whichever is later. If payment is not made within this period, interest may accrue on the unpaid amount. For private projects, according to Montana Code Annotated § 28-2-2101 et seq., the due date for payment by the owner to the contractor, and from the contractor to the subcontractor, must be disclosed in the contract, and if payment is not made by the due date, interest may also accrue. The statutes provide for a rate of interest on late payments and allow for the recovery of attorney fees and costs in the event of litigation to collect unpaid amounts. These laws are in place to protect the cash flow to businesses involved in construction and to discourage unnecessary payment delays.