Government contracting guide
FAR 52.232-25 Prompt Payment: The 40-Day Postmark Rule for Additional Interest Penalty Demands and the Fallback When the Postmark Is Missing
A contractor seeking an additional interest penalty under FAR 52.232-25 must meet three conditions: the Government owes at least $1 in late-payment interest, does not pay that interest within 10 days after paying the invoice amount, and receives a qualifying written demand postmarked no later than 40 days after that payment. If the postmark is absent or illegible, the clause provides an alternative validity sequence based first on the payment office's receipt annotation and then, if the office fails to annotate, on the date the contractor placed on the demand.
Requirements at a glance
| Requirement | FAR 52.232-25(a)(7) |
|---|---|
| Applicability | An additional interest penalty is available only when the Government owes an interest penalty of $1 or more and the designated payment office does not pay it within 10 days after payment of the invoice amount. |
| Timing | The written demand must be postmarked no later than 40 days after the invoice amount is paid. The clause uses calendar days unless otherwise specified. |
| Demand content | Identify the specific invoice, assert that late-payment interest is due, request overdue interest and any additional penalty due, attach a copy of the invoice, and state that principal was received and the date of receipt. |
| Delivery evidence | The clause does not require Certified Mail or prescribe a single delivery method. A postmark establishes timeliness; if it is missing or illegible, the clause provides a receipt-annotation and contractor-date fallback. |
| Exceptions and authority | The additional penalty does not apply to payments regulated by other Government regulations, such as certain utility payments subject to tariffs. See FAR 52.232-25 and 5 CFR 1315. |
Separate the base interest penalty from the additional penalty
The clause distinguishes between late-payment interest on the invoice and an additional penalty for the Government's failure to pay that interest. Under paragraph (a)(4), the designated payment office pays an eligible late-payment interest penalty automatically, without a contractor request. The clause's conditions include receipt of a proper invoice, a processed receiving report without disagreement, and a final invoice not subject to settlement actions.
The additional penalty under paragraph (a)(7) is different. It depends on the three conditions in the table, including a timely written demand. The 40-day clock begins when the invoice amount is paid, not when the original invoice was due or when the contractor discovers that interest remains unpaid.
For this clause, payment is considered made on the date of the check or the date of the electronic funds transfer. Keep evidence of that date with the demand file. The additional penalty amount is calculated under the prompt payment regulations in 5 CFR Part 1315. The applicable interest rate varies by period; this article does not state a rate.
Follow the postmark and fallback sequence
The clause makes the postmark the ordinary timing evidence. A demand postmarked on or before the 40th day meets the clause's mailing-date requirement, subject to the other eligibility and content conditions.
If there is no postmark or it is illegible, FAR 52.232-25(a)(7)(ii)(B) sets out a two-step fallback:
- Payment-office annotation. The designated payment office that receives the demand annotates it with the date of receipt, provided it receives the demand on or before day 40.
- Contractor-date fallback. If the office fails to make that annotation, the Government determines validity using the date the contractor placed on the demand, provided that date is no later than day 40.
This is an alternative-validity ladder, not a reason to leave mailing evidence uncollected. Retain the postmarked record when available. If the postmark is absent or unclear, preserve proof of when the office received the demand and, where relevant, a copy showing the date placed on it.
The clause does not require Certified Mail. A Certificate of Mailing or Certified Mail record can provide useful supporting evidence of the mailing event, but it does not replace the demand's required content or extend the deadline. See also the related guidance on what the postmark rule requires and proof of mailing versus proof of notice.
Prepare a complete written demand
FAR 52.232-25(a)(7)(ii)(A) specifies the information the contractor must provide. The clause says the Government will not request additional data. Before sending, confirm that the demand:
- Specifically asserts that late-payment interest is due under the identified invoice.
- Requests payment of all overdue late-payment interest and any additional penalty that may be required.
- Includes a copy of the invoice on which the unpaid interest is due.
- States that principal payment was received and gives the date of receipt.
Link the demand and attachment to the payment record for that invoice. Do not assume that an invoice reference alone satisfies the requirement to attach an invoice copy. The demand should go to the designated payment office identified for the contract.
The base interest penalty and additional penalty are calculated under the prompt payment regulations. For the base penalty, FAR 52.232-25 generally sets the payment due date at the later of 30 days after receipt of a proper invoice or 30 days after Government acceptance. For penalty computation, constructive acceptance generally occurs on the seventh day after delivery, unless the contract specifies otherwise. An improper invoice should be returned with reasons within seven days; untimely notification is taken into account when computing any interest penalty owed.
Build the evidence file as the notice is prepared
A complete file should enable a reviewer to verify eligibility, calculate the deadline, inspect the demand, and confirm the mailing or receipt evidence without reconstructing the sequence from separate inboxes.
Additional interest penalty demand file checklist
- Contract and applicable Prompt Payment clause.
- Invoice copy and invoice identifier.
- Record showing the invoice amount payment date, such as check date or EFT date.
- Record supporting the unpaid base interest penalty and the 10-day nonpayment condition.
- Final written demand containing all required assertions and statements.
- Copy of the invoice attached to the demand.
- Postmark evidence, if present and legible.
- If the postmark is missing or illegible, payment-office receipt annotation dated no later than day 40.
- If the office fails to annotate, a copy of the demand showing the contractor's date, no later than day 40.
- Copy of the complete package as sent and any related correspondence.
Assign an owner to calculate the 40-day deadline when principal payment is recorded. Include an internal review date before the deadline, verify the payment office's submission instructions, and retain the completed file in a controlled location. These steps preserve deadline evidence and clarify responsibility across finance and contracts teams.
For related federal-contract notice guidance, see the Government contracting notices hub. The audit-trail framework for legal notices provides further guidance on linking requirements, actions, and retained evidence.
Primary sources
National Compliance Registry provides compliance registration and record-management services focused on controlled records and reviewable evidence.
This article provides general compliance information, not legal advice.