What is Inventorship?
The conception test, what joint inventors must and need not share, how to correct a mistake, what happens when a true inventor is left off, and the current rules for AI-assisted inventions.
Definition
Inventorship is the legal determination of which individuals conceived the invention defined by the claims of a patent application. Every person who contributed to the conception of at least one claim must be named as an inventor, and no one who did not may be, regardless of employment, seniority, or who did the work of reducing the invention to practice.
Key Facts
- Test: Conception, meaning the formation in the inventor's mind of a definite and permanent idea of the complete and operative invention; reducing it to practice under someone else's direction is not inventorship
- Claim by claim: Inventorship is determined against the claims as they stand; amending the claims can change who the inventors are
- Joint inventors: Need not work together at the same time, contribute equally, or contribute to every claim, under 35 U.S.C. § 116
- Ownership is separate: Inventors own the patent by default; the employer acquires it only by assignment
- Each joint owner may license the whole patent without the others' consent unless an agreement says otherwise
- Correction: Errors made without deceptive intent are corrected under 35 U.S.C. § 256 during prosecution or after grant
- AI: Only natural persons can be inventors; under the USPTO's 2024 guidance, a person using AI must have made a significant contribution to the conception of each claim
Who Is and Is Not an Inventor
An inventor contributed to conceiving what is claimed. A person who suggested the problem, provided funding, supervised the lab, ran the experiments the inventor designed, or built the prototype to the inventor's specification is not, however important their role. A person who contributed one limitation to one dependent claim is a joint inventor of the patent. The determination should be made by counsel from the invention disclosure and the contributors' own accounts, and revisited when claims are amended or a continuation is filed with different claims.
Why It Matters
- Validity: A patent that names the wrong inventors can be invalidated if the error was deceptive, and must be corrected if it was not
- Ownership: An omitted inventor who never assigned owns an undivided interest and can license the patent to anyone, including a competitor, as happened in Ethicon v. U.S. Surgical
- Standing: All owners must join an infringement suit; a missing co-owner can block enforcement
- Micro entity status depends on each inventor's filing history and income
- Recognition and awards: Inventor compensation programs and, in some countries, statutory employee-inventor remuneration turn on being named
Correcting Inventorship
During prosecution, inventorship is corrected by a request under 37 C.F.R. § 1.48 with a statement from each added or removed person and, where needed, a new declaration. After grant, a certificate of correction under § 256 or a court order does the same. Either way, an assignment from any newly added inventor is required to keep title intact.
AI-Assisted Inventions
Following Thaler v. Vidal (2022), an AI system cannot be named as an inventor. The USPTO's February 2024 guidance applies the joint inventorship "significant contribution" standard to people who use AI: prompting a system with a problem is not enough, but designing the prompts, recognizing and developing a meaningful output, or building the model for the specific problem can be. Disclosure processes now need to record how AI was used so counsel can make that determination.
Frequently Asked Questions
Don't see the answer you're looking for?
Feel free to reach out to us for more info.
Who should be listed as an inventor on a patent?
Every person who contributed to the conception of at least one claim, and no one else. Conception means forming the definite idea of the invention, not carrying out the work. A manager who assigned the project, a technician who followed instructions, and a funder are not inventors; a colleague who contributed one claimed feature is.
What happens if an inventor is left off a patent?
If the omission was not deceptive, inventorship can be corrected under 35 U.S.C. § 256. Until it is, the omitted inventor owns an undivided share of the patent, can license it to anyone without accounting to the others, and must join any infringement suit. If the omission was deliberate, the patent can be held invalid or unenforceable.
Can inventorship be corrected after the patent issues?
Yes. Under 35 U.S.C. § 256 the USPTO issues a certificate of correction on application by all parties and assignees, or a court can order correction. The error must have been made without deceptive intent. An assignment should be obtained from any added inventor at the same time.
Do joint inventors have to contribute equally?
No. Under 35 U.S.C. § 116, joint inventors need not have worked together physically or at the same time, made the same type or amount of contribution, or contributed to every claim. A contribution to the conception of a single claim is enough.
Can an AI system be named as an inventor?
No. Thaler v. Vidal (Fed. Cir. 2022) held that inventors must be natural persons. Under the USPTO's 2024 guidance, a person who uses AI can be an inventor only if they made a significant contribution to the conception of the claim, such as designing the prompts or recognizing and developing a meaningful output; merely presenting a problem to the system is not enough.
Power Every Patent Decision
With One Platform
See how ArcPrime connects your portfolio, workflows, and business context to help your team make better decisions across the patent lifecycle.