What is the duty of candor and good faith before the USPTO?

The duty of candor and good faith is the affirmative obligation that 37 CFR 1.56 imposes on everyone involved in prosecuting a U.S. patent application. It requires each of them to disclose to the USPTO all information they know to be material to patentability, and to deal honestly with the Office throughout prosecution.

The regulation traces the duty to a public-interest rationale: a patent by its very nature is affected with a public interest, and the most effective patent examination occurs when, at the time an application is being examined, the Office is aware of and evaluates the teachings of all information material to patentability.

The regulatory foundation

The duty is codified in 37 CFR 1.56. Each individual associated with the filing and prosecution of a patent application has a duty of candor and good faith in dealing with the Office, and must disclose to the Office all information known to that individual to be material to patentability.

Who has the duty

The duty falls on individuals, not on organizations themselves. Under 37 CFR 1.56(c), three categories of individuals bear the obligation: (1) each inventor named in the application; (2) each attorney or agent who prepares or prosecutes the application; and (3) every other person who is substantively involved in the preparation or prosecution of the application and who is associated with the inventor, applicant, or assignee.

The third category is intentionally broad. In-house patent counsel, a technical employee who participates in prosecution strategy discussions, or a foreign patent attorney prosecuting a counterpart application on behalf of the same applicant can each fall within it.

Individuals in the third category who are not the attorney, agent, or inventor of record may comply with the duty by disclosing material information to the attorney, agent, or inventor handling the U.S. application. That attorney, agent, or inventor, who is already subject to the duty, then handles getting the information before the Office.

What must be disclosed: the materiality standard

The duty requires disclosure of information that is "material to patentability." Under 37 CFR 1.56(b), information is material when it is not cumulative to information already of record, and either (1) establishes, by itself or in combination with other information, a prima facie case of unpatentability of a claim, or (2) refutes or is inconsistent with a position the applicant takes in opposing an argument of unpatentability relied on by the Office or in asserting an argument of patentability.

Cumulative information does not have to be disclosed: if a reference duplicates the substance of what the examiner already has in the record, it falls outside the duty. That exception is narrow in practice. A reference that makes the same general point as a cited reference but is technically closer to the claimed invention may not be genuinely cumulative.

The duty also extends well beyond prior art patents and publications. Material information subject to the duty includes information about enablement, prior public uses and sales, inventorship conflicts, litigation-related statements, and information submitted to regulatory agencies such as the FDA. Practitioners who confine their disclosure review to a prior art search are working with an incomplete picture of what 37 CFR 1.56 requires.

Omissions and affirmative misrepresentations

The duty covers both types of conduct. Failing to disclose known material information is the more commonly discussed scenario, but the duty equally reaches affirmative representations made to the Office: if a party discovers that an earlier position taken in a submission to the USPTO was incorrect or inconsistent with other statements, the party must promptly correct the record.

MPEP 2004 specifically instructs that prior art citations must be properly described and not incorrectly or incompletely characterized, and that foreign counsel representing applicants for U.S. patents must meet the same standards of conduct as U.S. counsel. A declaration that overstates experimental results, an argument that mischaracterizes what a reference teaches, or a representation about the state of the art that the applicant later discovers is false can all implicate the duty.

How long the duty lasts

The duty does not end at filing. It continues for each pending claim until that claim is cancelled, withdrawn from consideration, or the application becomes abandoned. New material information encountered mid-prosecution, such as art cited in a foreign counterpart office action or produced in related litigation, must be evaluated promptly and disclosed if it meets the materiality standard.

For continuation-in-part applications, the duty applies to information that became available between the filing date of the prior application and the filing date of the CIP. This captures newly relevant disclosures that emerged in the gap between the two filings.

How to fulfill the duty

The provisions of 37 CFR 1.97 and 37 CFR 1.98 provide a structured mechanism for complying with the duty of disclosure using an Information Disclosure Statement (IDS). Filing an IDS as early in prosecution as possible is advisable, because different timing windows under 37 CFR 1.97 carry different administrative requirements, with later windows requiring certification statements or fees that the earliest window does not. See the dedicated page on Information Disclosure Statements for the full timing rules, required content, and certification statement details.

Importantly, filing an IDS is not an admission that the cited information is, or is considered to be, material to patentability. Practitioners should include borderline references rather than gamble on a materiality judgment. When the materiality of a reference is uncertain, MPEP 2004 guidance is explicit: submit the information and let the examiner decide.

Consequences of violation

Violation of the duty operates at two levels.

At the administrative level, 37 CFR 1.56 provides that no patent will be granted on an application in connection with which fraud on the Office was practiced or attempted, or the duty of disclosure was violated through bad faith or intentional misconduct.

At the judicial level, a finding of inequitable conduct renders every claim in the patent unenforceable, not just the claims directly connected to the misconduct. This all-or-nothing consequence is among the most severe sanctions in U.S. patent law.

The USPTO itself does not investigate or reject applications based on duty of disclosure violations; examiners note only that such issues are not considered during examination, and the determination of inequitable conduct is a judicial matter for courts to resolve.

Practical notes for practitioners

• The duty applies to individuals. A company cannot shift a disclosure obligation to an institution: the duty rested on each specific person who was substantively involved in the prosecution.
• Filing an IDS shall not be construed as an admission that the cited information is material to patentability. Over-disclosure is the safer practice.
• A violation of the duty can result in a finding that no patent may be granted on the application, and if the application has already issued, that all claims are unenforceable. For the litigation test courts apply to evaluate such breaches, including the Therasense but-for materiality standard and specific intent requirement, see the page on inequitable conduct in patent law.