subsectionUpdated April 16, 2026

    FAR 32.608-1Interest charges.

    Plain-English Summary

    FAR 32.608-1 explains when the Government may assess interest on a contract debt and when it may not. It ties the interest rule to the standard contract clause at 52.232-17, Interest, and states the default timing: interest begins to apply to an unpaid contract debt after 30 days from the issuance of a demand. The section also identifies two exceptions: debts under contract types excluded by FAR 32.611 and debts or contracts that an agency has exempted from interest charges under its own procedures. In practice, this provision matters because it affects how quickly unpaid debts grow, how agencies manage collection actions, and how contractors evaluate the cost of delaying payment or disputing a debt. It also signals that interest is not automatic in every case; the contract clause, the contract type, and agency-level exemptions all matter.

    Key Rules

    Interest starts after 30 days

    Unless the contract clause says otherwise, interest charges apply to any contract debt that remains unpaid 30 days after the Government issues a demand. The 30-day clock is the key trigger for when interest begins to accrue.

    Clause controls if different

    The rule applies unless the clause at 52.232-17, Interest, specifies a different treatment. That means the contract’s incorporated interest clause can modify how interest is assessed.

    Excluded contract types

    No interest is charged if the contract is a type excluded under FAR 32.611. The debt may still be owed, but this section does not authorize interest on those excluded contracts.

    Agency exemptions allowed

    An agency may exempt a contract or a specific debt from interest charges under its own procedures. Those agency procedures can remove or limit interest even when the general rule would otherwise apply.

    Responsibilities

    Contracting Officer

    Issue the demand for payment, determine whether the debt is subject to interest under the contract clause and FAR 32.611, and apply any agency exemption procedures before assessing interest.

    Agency

    Establish and follow procedures for exempting contracts or debts from interest charges, and ensure those procedures are applied consistently.

    Contractor

    Pay any demanded contract debt within 30 days to avoid interest, or promptly raise any dispute or request for relief if the debt is believed to be incorrect or exempt.

    Practical Implications

    1

    The 30-day demand date is critical; missing it can turn a principal debt into a larger debt with interest added.

    2

    Contractors should check the contract clause and contract type before assuming interest will or will not apply.

    3

    Agencies need to verify whether a debt falls under an excluded contract category or an approved exemption before billing interest.

    4

    A common pitfall is treating every unpaid debt the same; this section requires attention to the specific contract, clause, and agency procedures.

    5

    Even when interest is not charged, the underlying debt may still be collectible, so exemption from interest does not necessarily mean forgiveness of the debt.

    Official Regulatory Text

    Unless specified otherwise in the clause at 52.232-17 , Interest, interest charges shall apply to any contract debt unpaid after 30 days from the issuance of a demand unless- (a) The contract is a kind excluded under 32.611 ; or (b) The contract or debt has been exempted from interest charges under agency procedures.