The short answer: Since the America Invents Act, federal law (35 U.S.C. § 298) has barred patent owners from using a company's failure to obtain — or to show the court — an opinion of counsel to prove willful infringement or inducement. But a well‑reasoned opinion remains one of the best tools to defend against enhanced damages.
How it works
Courts may increase damages up to three times for egregious, willful infringement (35 U.S.C. § 284; Halo Electronics v. Pulse Electronics, 2016). Willfulness turns on what the accused infringer knew and believed. Section 298 means silence about counsel's advice isn't evidence against you — but it also isn't evidence for you.
A competent opinion, obtained when you learn of a patent and based on a careful analysis of the claims, file history and prior art, gives a jury concrete evidence of good‑faith belief in non‑infringement or invalidity.
Example: A chemical manufacturer receives a competitor's letter citing a process patent. It obtains a written non‑infringement opinion explaining why its process operates outside the claimed parameters, and adjusts its controls accordingly. If sued, the opinion can support a defense against willfulness and inducement.
One caution: Relying on an opinion at trial generally waives privilege over communications on the same subject — so plan opinion strategy with litigation counsel.
What to do
- Get an opinion promptly after receiving notice of a relevant patent.
- Make it substantive — claim‑by‑claim, file history, prior art — not a conclusory letter.
- Revisit it when the product, process or the patent changes.
Sources
- 35 U.S.C. 298
- 35 U.S.C. 294
- Halo Elecs., Inc. v. Pulse Elecs., Inc. 579 U.S. 93 (2016)
- In re EchoStar Commc'ns Corp., 448 F.3d 1294 (Fed. Cir. 2006) (scope of privilege waiver)
Need an opinion of counsel or freedom‑to‑operate analysis?
Contact Green, Griffith & Associates LLP to discuss your patent strategy.