Imagine That IP Law Blog

Attorney-client privilege is a longstanding and foundational legal doctrine. This privilege is meant to promote open communication between attorneys and their clients. Therefore, it not only protects the legal advice given by an attorney, but also the information from a client. This open communication enables attorneys to give informed and sound legal advice. Upjohn Co. v. United States, 449 U.S. 383, 390 (1981). For a communication to be protected by the attorney-client privilege, it needs to be confidential, it must be between the attorney and the client, and it must be for the purpose of seeking or providing legal advice. Significantly, this privilege and the corresponding standard are equally applicable in the context of patent prosecution. The exact contours of the application of the attorney-client privilege to patent prosecution are discussed below.

The Supreme Court has long established the preparation and prosecution of a patent application constitutes practicing law, and thus, attorney-client privilege extends to the prosecution process. Sperry v. Fla., 373 U.S. 379, 383 (1963). During the prosecution of a patent, a communication is likely to be covered by the attorney-client privilege when the communication is for the purpose of obtaining legal advice on patentability and legal services in preparing a patent application. In re Spalding Sports Worldwide Inc.,203 F.3d 800, 806 (Fed. Cir. 2000). The presence of a discussion of publicly available prior art (such as patent publications) or technical information in a communication between a patent attorney and an inventor does not, by itself, mean attorney-client privilege cannot be applied. Rather, such communications can still be protected so long as they meet the other criteria for an attorney-client communication. Id. The key point is the communication needs to be for the purpose of obtaining or giving legal advice, whether explicitly or implicitly stated. Id.

In the context of patent prosecution, privilege does not just apply to communications with attorneys. Federal courts and the United States Patent and Trademark Office (USPTO) have both acknowledged a privilege that exists between patent agents (those who have passed the USPTO Patent Bar, but are not attorneys) and clients. However, that privilege is more limited than between attorneys and clients. A communication between a patent agent and client is privileged if it is in furtherance of the patent agent’s abilities under 37 C.F.R. § 11.5 or if it is “reasonably necessary and incident to the preparation and prosecution of patent applications.” In re Queen’s Univ., 820 F.3d 1287, 1301 (Fed. Cir. 2016). However, if a communication is not reasonably necessary or incident to prosecution, it falls outside the scope of the patent agent-client privilege. Examples of communications that fall outside the patent agent-client privilege are when patent agents offer an opinion on the validity of a third party patent, on patent infringement, or on the sale or purchase of a patent. Id. at 1301-02.

Litigation often leads to major disputes over whether communications are protected by the attorney-client privilege. There are some common pitfalls that lead to a purported attorney-client communication being contested and deemed not privileged upon closer scrutiny. Communications with in-house counsel are highly scrutinized to ensure they were for the purpose of providing legal advice, rather than for more general business advice. In the context of patent prosecution, communications provided for the purpose of evaluating the technical or business merits of an invention, rather than an invention’s patentability or how to best protect the invention, can also come under the microscope. Again, communications that are not for the purpose of providing legal advice in the context of patent prosecution may fall outside the privilege. Raytheon Co. v. Cray, Inc., 2017 U.S. Dist. LEXIS 85563 (E.D. Tex. June 5, 2017).

This highlights the importance of keeping communications regarding business recommendations separate from legal analysis in order to maintain the privilege. In some circumstances, this can prove challenging. For example, discussions relating to licensing and royalties often blend legal considerations with business factors, with legal advice being the foundation of important client decisions. This tension may be mitigated by explicitly framing communications as requesting or giving legal advice that guides business decision-making, thus reinforcing that the communication should be protected by the applicable privilege.

Another common pitfall occurs when clients unintentionally waive the privilege. This often happens when clients share communications with third parties, overly distribute attorney correspondence, or otherwise lost control over the dissemination of attorney communications. One common example relates to a client simply copying an attorney on an email that is not otherwise a request for legal advice. Another example is when the client forwards otherwise privileged emails without including an attorney. Both scenarios can arguably lead to a waiver of the attorney-client privilege, and the results can be severe.

 For these reasons, it is important to ensure clients are educated regarding the attorney-client privilege, and learn to take measures to maintain privilege and avoid unintentional waivers. A practical way to achieve this is through implementing client training emphasizing thoughtful and intentional communication. This training should encourage clients to thoughtfully consider how communications with attorneys will be viewed years later, or if the client would be comfortable seeing the communication published on the internet or displayed before a jury. When communicating with counsel, clients should ensure that their communications are necessary, truthful, and concise. They should avoid hyperbole, characterizations, conjecture, and drawing legal conclusions. Ideally, they should direct the communications only to the correct recipients or audience using the appropriate methods of communication.

To summarize, while the attorney-client privilege provides critical protection during patent prosecution, its application is not absolute and can be lost. The scope of the privilege depends on the purpose of the communication, the role of the individuals involved, and the care taken to maintain and protect it. Communications will be closely scrutinized to ensure they are truly legal in nature, particularly when they also relate in some way to business considerations. Communications should be approached with intention and discipline by clearly framing communications as requests for legal advice and limiting the distribution. By doing so, parties can better preserve this critical privilege and reduce the risk it will be successfully contested.  

Reprinted with permission from the April 22, 2026 issue of The Legal Intelligencer ©2026 ALM Media Properties, LLC. Further duplication without permission is prohibited. All rights reserved.