35 USC 116: Joint Inventors, Corrections, and Filing Rules

35 U.S.C. 116 is the federal patent statute governing joint inventors. It does three jobs: it defines who qualifies as a joint inventor on an application, it lets the remaining inventors file when one refuses or cannot be found, and it gives the USPTO Director authority to correct inventorship errors on a pending application.¹

Who Counts as a Joint Inventor

Section 116(a) is more permissive than most people expect. Joint inventors can apply together even if they did not work in the same place, did not work at the same time, contributed different types or amounts of work, or contributed to only some of the claims. That last point catches people off guard. If a patent has twenty claims and your contribution shows up in one of them, you belong on the application.¹

What the statute does require is a contribution to conception. Conception means forming a definite idea of the complete invention — not wanting a result, but working out how to achieve it. Without a contribution to that mental act, a person is not an inventor no matter how much other labor they put into the project.²

Federal courts apply a three-part test. A person is a joint inventor when they contributed in some significant way to the conception or reduction to practice of the invention, when that contribution is not insignificant measured against the full invention, and when they did more than explain well-known concepts or the current state of the art to the actual inventors. All three prongs must be met.

Contributions That Do Not Qualify

Most inventorship disputes turn on this line. Helping an inventor after the idea has already been conceived is not co-inventorship. Building a prototype from someone else’s detailed instructions is reduction to practice, not conception, and a skilled technician following oral directions is treated as a technician.²

Someone who identifies a problem without a route to the solution is not a co-inventor either. Saying “we need a battery that lasts twice as long” states a goal. Working out how the battery does it is the inventive act. A person of ordinary skill in the field who carries out routine steps to make the invention work has not contributed to conception, even if the specification describes their particular version.

In everyday practice, lab technicians, machinists, and research assistants often do essential work on a patented invention without qualifying as inventors. Naming the wrong people, or leaving a real inventor off, can jeopardize the whole patent, so the line matters.

Some Actual Collaboration Is Required

Section 116(a) is broad, but the word “jointly” carries weight. In Kimberly-Clark Corp. v. Procter & Gamble Distributing Co., two engineers at the same company independently developed similar diaper designs years apart with no knowledge of each other’s work. The Federal Circuit held they could not be joint inventors, because the statute demands collaboration, shared direction, or at least one inventor building on the other’s disclosed work.³

The collaboration itself does not have to be elaborate. Reading a colleague’s internal report and building on an idea from it is enough. Hearing a suggestion in a meeting counts. But two people who are completely unaware of each other’s work — even on the same problem at the same company — cannot be joint inventors, however similar their results.³

Filing When a Joint Inventor Refuses or Cannot Be Found

Section 116(b) keeps one uncooperative person from killing an application. If a joint inventor refuses to join, or cannot be found after a genuine search, the remaining inventors can file without them. The USPTO reviews the facts, provides notice as appropriate, and can grant the patent subject to whatever rights the omitted inventor would have had. The missing inventor may join the application later by submitting a standard oath or declaration.¹

The Substitute Statement

For applications filed on or after September 16, 2012, the America Invents Act made the substitute statement the working mechanism for this situation. Under 37 CFR 1.64, a substitute statement can replace an inventor’s required oath or declaration when the inventor is deceased, legally incapacitated, unreachable after diligent effort, or has refused to sign.⁴

Whoever signs must have actually reviewed and understood the entire application, including the claims, and must be aware of the duty to disclose information affecting patentability. The statement identifies the signer, their relationship to the missing inventor, and the specific reason the inventor cannot sign. Willfully false statements carry federal criminal penalties of up to five years in prison.⁴

The Petition Fee

The USPTO charges a petition fee that scales with entity size. For a nonsigning-inventor petition, the undiscounted fee is $450, reduced to $180 for small entities and $90 for micro entities.⁵ Notice of the filing is published in the Official Gazette, which records publicly that the application went forward without the missing inventor.⁶

Correcting Inventorship on a Pending Application

Section 116(c) lets the Director fix inventorship errors on an application that has not yet issued. If someone was named who should not have been, or a real inventor was left off, the application can be amended.¹

A common misconception is that the applicant has to prove the mistake was innocent. Before 2011, the statute did require showing the error arose “without any deceptive intention.” The America Invents Act struck that language, and today the correction no longer turns on state of mind.⁷

The correction runs through 37 CFR 1.48, and the fee depends on timing. The general processing fee is $150 for large entities, $60 for small entities, and $30 for micro entities. If the correction comes after the first action on the merits, the fee climbs to $690, $276, or $138, respectively.⁸ Catching the mistake early saves real money and avoids the heavier petition process required after examination has started.

After the Patent Has Issued

Section 116 stops at the grant. Once a patent has issued, inventorship corrections run through 35 U.S.C. 256, which lets the Director issue a certificate correcting the error when all parties and assignees apply with proof of the relevant facts. A court hearing a case involving the patent can also order the correction directly. Incorrect inventorship does not automatically invalidate an issued patent so long as the error is correctable under Section 256.⁹

What Happens If Inventorship Is Wrong

Getting inventorship wrong has teeth. During prosecution, if the USPTO determines the application names the wrong people and the applicant does not fix it, the examiner can reject every claim under 35 U.S.C. 101 and 115. That is a rejection of the entire application, not just the claims tied to the disputed inventor.¹⁰

If a named inventor actually derived the invention from someone else, the true inventor can initiate a derivation proceeding under 35 U.S.C. 135. After issuance, inventorship becomes ammunition in litigation, and defendants routinely challenge patents by arguing the wrong people were named. Section 256 gives a path to correction that can save the patent, but an opponent may argue the error is not the kind that can be corrected, especially where there is evidence of intentional manipulation.

Every named inventor also has to execute an oath or declaration under 35 U.S.C. 115 confirming they believe themselves to be an original or joint inventor of a claimed invention, and the oath includes an acknowledgment that willfully false statements are punishable by fine or imprisonment. Naming someone who did not contribute to conception, or deliberately omitting a real inventor, carries potential criminal exposure on top of the patent validity risk.¹¹

What Being Named Actually Gets You

Section 116 decides who goes on the application. Section 262 decides what that name is worth, and the default surprises most people. Each joint owner of a patent can independently make, use, sell, or license the invention within the United States without asking the other owners and without sharing the money. There is no built-in duty to account to the other owners for profits.¹²

A co-inventor can grant an exclusive license to a competitor, collect all the royalties, and owe the other inventor nothing. The statute applies “in the absence of any agreement to the contrary,” so a written agreement is the only thing that changes the default.¹²

Employers usually handle this through assignment clauses in employment contracts that move each inventor’s rights to the company before the patent issues. When independent collaborators co-invent without a written agreement in place, the Section 262 default takes over, and the results can be harsh for the co-inventor who assumed good faith would carry the day. Anyone working on a joint invention outside a corporate employment setting should get an ownership agreement signed before the application is filed.

1
Office of the Law Revision Counsel. 35 USC 116 – Inventors
2
United States Patent and Trademark Office. Manual of Patent Examining Procedure Section 2109 – Inventorship
3
Justia Law. Kimberly-Clark Corporation v. The Procter and Gamble Distributing Co.
4
eCFR. 37 CFR 1.64 – Substitute Statement in Lieu of an Oath or Declaration
5
United States Patent and Trademark Office. USPTO Fee Schedule
6
United States Patent and Trademark Office. Manual of Patent Examining Procedure Section 1703 – The Official Gazette
7
Office of the Law Revision Counsel. 35 USC 116 – Inventors
8
eCFR. 37 CFR 1.17 – Patent Application and Reexamination Processing Fees
9
Office of the Law Revision Counsel. 35 USC 256 – Correction of Named Inventor
10
United States Patent and Trademark Office. Manual of Patent Examining Procedure Section 2157 – Improper Naming of Inventors
11
Office of the Law Revision Counsel. 35 USC 115 – Inventor’s Oath or Declaration
12
Office of the Law Revision Counsel. 35 USC 262 – Joint Owners