When Is an Invoice Really an Invoice?

By Jon Straw

All court decisions are opinions. Appellate court decisions are typically made by a panel of three judges. Here, after a dispute arose 19 years earlier, two judges formed the majority opinion, described below. The third judge disagreed and wrote a dissenting opinion, also described below. With whom would you agree?

Facts

In 2006, a supplier agreed to provide precast panels for sound barrier walls to a highway contractor for a project near Moses Lake, Wash. Under the contract, progress payments were due from contractor to supplier within 15 days of supplier’s submission of each invoice. Final payment was due within 30 days of completion. Extra costs “will be presented” by supplier and paid by contractor. Interest would accrue on “late payments.”

The contractor directed changes to the supplier’s casting methods, including: One, no usage of curing accelerators and, two, stripping molds after achieving 70 percent of breaking strength, rather than the standard 50 percent. The project was substantially completed in November 2007.

In January 2008, the supplier sued the contractor for extra costs. In February 2008, the supplier submitted a 72-page document to the contractor entitled “overruns” totaling over $1.3 million. During trial, the supplier described the document as an “estimate.” The contractor described the document as a detailed breakdown of extra costs incurred by the supplier. Before trial, the supplier’s accountant determined the actual cost overrun was less, so the supplier reduced its claimed damages.

A jury awarded the supplier 70% of its actual, principal damages, which was not overturned on appeal. Cascade Concrete Industries, Inc. v. Central Washington Asphalt, Inc. and Safeco Insurance Co. of America, 2025 WL 3719633 (Court of Appeals of Washington, Div. 3, Dec. 23, 2025).

Majority Opinion

The trial court denied prejudgment interest reasoning the “estimate” was preliminary, uncertain and not an invoice, so interest could not accrue on an uncertain amount. The contract did not define an invoice, so the trial court reasoned with support from a dictionary that an invoice was a statement of actual amount due. The appellate court agreed reasoning that prejudgment interest does not accrue on an unliquidated or uncertain amount. The trial and appellate courts further reasoned the damages sought were not certain because the jury awarded only 70%, not 100%, of the reduced damages sought by supplier.

The trial court denied post-judgment interest at the contractual rate of 18% and instead applied the statutory rate of 12% from the time that the jury rendered the verdict. The trial court reasoned that the contractual rate only if an invoice was previously submitted. The appellate court agreed.

Dissenting Opinion

The dissenting judge opined that invoices were necessary for progress payments within the original scope of work, but that invoices were not required for payment of extra costs. Invoices were not necessary for prejudgment interest on extra costs because: One, the contract terms required only that costs for extras “will be presented” by supplier to contractor and paid by contractor and, two, final payment was due within 30 days of completion, without any contractual requirement for an invoice.

The dissent further reasoned that a reduction in the principal amount claimed or awarded does not prevent interest. For the same reasons, post-judgment interest should have been at the contractual not the statutory rate since no invoice was necessary for interest to accrue on extra costs. Although opining that an invoice was not necessary, the dissent nevertheless concluded that the 72-page detailed description actually met the requirements for an invoice with support from various dictionaries.

Conclusion

Although the majority controls, the dissent’s reasoning is compelling. With which do you agree? As any dispute progresses to later stages such as trial or arbitration, the parties release more control to other decision-makers. When others decide, there may be no clear winner. To maintain control and reduce uncertainty, strive to resolve disputes earlier.

Jon Straw is a partner with Kraftson Caudle, PLC, a law firm in McLean, Va., specializing in heavy-highway and transportation construction. Straw can be contacted via email at [email protected].