Under U.S. patent law, the person who can apply for a patent is the inventor: the natural human being who conceived the invention. That is the default rule, and it is a strict one. The Patent Act requires that an application “shall be made, or authorized to be made, by the inventor,”1Office of the Law Revision Counsel. 35 U.S. Code 111 – Application and it defines an inventor as “the individual or, if a joint invention, the individuals collectively who invented or discovered the subject matter of the invention.”2Office of the Law Revision Counsel. 35 USC 100 – Definitions The law does allow certain other parties to file the paperwork on the inventor’s behalf, including employers who hold an assignment, legal representatives of a deceased or incapacitated inventor, and people with a sufficient ownership interest. But the inventor must always be identified, and the inventor must always be a person.
What Makes Someone an Inventor
Inventorship turns on conception. Conception means forming a complete mental picture of the finished invention, detailed enough that someone skilled in the relevant field could build it without needing to do significant additional research.3United States Patent and Trademark Office. MPEP 2109 – Inventorship The USPTO’s examination guidelines are blunt about what does not count: merely suggesting a desired result without identifying how to achieve it is not inventorship.
That rules out several people who are often assumed to be inventors. The person who builds the prototype is not the inventor, unless they also contributed to the conception. The investor who funded the research is not the inventor. The manager who supervised the project is not the inventor. The employee who ran routine tests, followed instructions, or gave general encouragement is not the inventor. Only the person or people who actually conceived the invention qualify.
Only a Human Being Can Be Named
The word “individual” in the Patent Act does real work. The Federal Circuit ruled in 2022 that it means a natural human being, and that an artificial intelligence system cannot be listed as an inventor.4U.S. Court of Appeals for the Federal Circuit. Thaler v Vidal, 43 F.4th 1207 The court found the statute unambiguous: “Congress has determined that only a natural person can be an inventor, so AI cannot be.” Corporations, partnerships, and other non-human entities are equally ineligible to be named as inventors, though they can and often do own patents through assignment.
Using AI tools during the inventive process is a separate question. The USPTO has clarified that patents for AI-assisted inventions are allowed, so long as the application names the natural person who made a significant intellectual contribution to the invention.5United States Patent and Trademark Office. Artificial Intelligence (AI) Guidance Update AI can be a tool. It cannot be a co-inventor.
When Two or More People Invent Together
Collaboration is common, and the law accommodates it. When two or more people jointly create an invention, they must apply for the patent jointly.6Office of the Law Revision Counsel. 35 U.S. Code 116 – Inventors The statute is deliberately flexible about what that collaboration looks like. Joint inventors do not have to work in the same location, work at the same time, or make contributions of the same type or size. They do not each have to contribute to every claim in the patent.
The threshold is contributing to the conception of at least one claim (the numbered statements at the end of the patent that define what it protects). Someone who cleared that bar is a joint inventor and must be listed. Someone who did not clear it should not be listed, even if they were closely involved in the project. Naming a non-inventor is just as problematic as omitting a real one.
Employers, Assignees, and Others Who Can File
The inventor must be identified on every application, but the party who actually files it can be someone else. Federal law lets anyone to whom the inventor has assigned the invention (or anyone owed such an assignment) file the application. A person with a sufficient ownership interest can also file by demonstrating that interest to the USPTO.7Office of the Law Revision Counsel. 35 U.S. Code 118 – Filing by Other Than Inventor
Assignments have to be in writing. The Patent Act is explicit that patents and patent applications “shall be assignable in law by an instrument in writing.”8Office of the Law Revision Counsel. 35 U.S. Code 261 – Ownership; Assignment A verbal promise to hand over patent rights will not do the job.
The most common version is the employment situation. Many employment agreements require workers to assign inventions created within the scope of the job. When that happens, the employee is still named as the inventor on the patent, but the employer files the application and owns the resulting patent. The USPTO recommends recording the assignment with its Assignment Division within three months of execution.
Filing After Death or Incapacity
The law also plans for situations where the inventor cannot personally participate. If an inventor has died, the legal representative of their estate can file the application. If an inventor is legally incapacitated, their guardian can file. In both cases, the representative acts on the same terms and under the same conditions that would apply to the inventor.9Office of the Law Revision Counsel. 35 U.S. Code 117 – Death or Incapacity of Inventor
This is not the same thing as assignment. A legal representative stands in for the inventor rather than owning the invention outright. Their authority comes from probate court or guardianship proceedings, not from a written transfer of rights.
When a Co-Inventor Refuses to Sign
Every named inventor normally has to sign an oath or declaration confirming they are the original inventor of the claimed invention. That requirement can create trouble when a co-inventor is uncooperative, but a missing signature does not have to sink the application. The USPTO allows a substitute statement to be filed in place of the oath when an inventor has refused to execute the required declaration.10United States Patent and Trademark Office. MPEP 604 – Substitute Statements
The substitute statement must identify the refusing inventor by legal name and last known address, explain the circumstances, and include the same content a regular declaration would contain. The signer must confirm they have reviewed and understood the full application and are aware of the duty to disclose information relevant to patentability. The same procedure covers inventors who cannot be located after a diligent effort.
No Citizenship or Age Requirements
U.S. patent law imposes no citizenship, residency, or nationality condition. An inventor from any country has the same right to file as a U.S. citizen.11U.S. Department of State Foreign Affairs Manual. 7 FAM 880 Federal and State Agency Documents There is also no minimum age. A teenager who conceives a patentable invention has the full legal right to be named as the inventor and granted the patent. A minor may need a parent or guardian for the procedural and financial side, but age alone never disqualifies an inventor.
Fixing Inventorship Mistakes
Getting the list of inventors wrong is more common than people expect, especially in corporate research where many hands touch a project. A good-faith mistake will not automatically destroy the patent. Federal law provides that “the error of omitting inventors or naming persons who are not inventors shall not invalidate the patent,” so long as it can be corrected.12BitLaw. 35 U.S.C. 256 – Correction of Named Inventor A court can order a correction, and the USPTO will issue an updated certificate.
That protection is only for honest errors. Deliberate fraud (intentionally omitting a real inventor or knowingly adding someone who did not contribute in order to deceive the USPTO) leaves the patent open to invalidation. The best defense against either outcome is documenting each person’s contribution to the inventive concept as the work happens, so the inventorship determination rests on a factual record rather than on memory years later.