Thaler v. Comptroller-General of Patents, Designs and Trademarks

Thaler v. Comptroller-General is the UK Supreme Court's ruling on AI inventorship, and it aligned the UK with the U.S. position. In December 2023, the court unanimously held that an inventor must be a natural person under the UK Patents Act 1977. But it left a door open that the U.S. courts didn't: the possibility that a human could claim inventorship when using AI as a "highly sophisticated tool."

Background

Stephen Thaler filed the same DABUS patent applications in the UK that he filed in the United States. He named his AI system DABUS as the inventor on applications for the same two inventions: a fractal-shaped food container and an emergency light beacon.

The UK Intellectual Property Office rejected the applications on the same grounds as the USPTO: an inventor must be a natural person. Thaler appealed through the UK court system, first to the High Court, then to the Court of Appeal, and finally to the UK Supreme Court.

The case attracted significant attention from the global patent community because the UK Supreme Court is one of the world's most influential courts for intellectual property law. Its decision would signal the direction for other common law jurisdictions considering the same question.

What Happened

The UK Supreme Court heard arguments in March 2023 and issued its decision on December 20, 2023. Lord Kitchin wrote for a unanimous court. The panel considered whether the Patents Act 1977 requires inventors to be natural persons and whether Thaler could derive patent rights from an AI inventor.

Thaler's legal team argued that the Patents Act doesn't explicitly require human inventorship and that excluding AI inventors would hinder innovation. They contended that Thaler, as the owner and operator of DABUS, should be able to claim patent rights as the successor in title to the AI's inventive output.

The UK Intellectual Property Office and other interveners argued that the statutory scheme assumes human inventors at every level. The patent system grants exclusive rights as an incentive for human innovation, and extending those rights to AI-generated inventions without any human inventive contribution would distort the system's purpose.

The Ruling

The UK Supreme Court unanimously dismissed Thaler's appeal. Lord Kitchin's opinion held that under the Patents Act 1977, an inventor must be a natural person. DABUS, as an AI system, cannot be named as an inventor on a patent application.

The court also rejected Thaler's argument that he could derive patent rights from DABUS as its owner. The statutory framework requires identifying a human inventor, and since DABUS isn't one, there's no inventive contribution from which Thaler can derive rights.

Critically, the court added language that distinguished its ruling from the more absolute U.S. position. Lord Kitchin noted that the court did not foreclose that a person could claim inventorship when using AI as a "highly sophisticated tool" to devise an invention. This left open the possibility that a human who uses AI as an instrument in the inventive process, rather than claiming the AI invented something independently, could still qualify as the inventor.

Outcome: The UK Supreme Court unanimously dismissed the appeal, holding that an inventor must be a natural person under the Patents Act 1977. An AI system cannot be named as an inventor.

Why This Case Matters

The ruling aligned the UK with the United States, the European Patent Office, and most major patent jurisdictions on the fundamental question: AI can't be an inventor. The DABUS applications were rejected across nearly every jurisdiction where they were filed. South Africa initially granted a patent listing DABUS as inventor but later reversed course.

The "highly sophisticated tool" language is the most significant aspect of this ruling for practicing attorneys. While the U.S. Federal Circuit's opinion in Thaler v. Vidal focused narrowly on statutory text, the UK Supreme Court explicitly acknowledged that AI-as-tool is a different question from AI-as-inventor. This distinction gives patent attorneys a framework for claiming human inventorship in cases where AI played a significant role in the development process.

The global consensus on AI inventorship creates practical clarity for multinational companies and their patent counsel. A uniform rule, human inventors required, simplifies patent prosecution strategy across jurisdictions. Companies don't need different inventorship frameworks for different countries. They need one approach: document the human contribution and name the human inventor.

Lessons for Attorneys

For patent attorneys handling international filings, the global consensus simplifies strategy. The UK, U.S., EU, and most major jurisdictions require human inventors. Build a single inventorship documentation framework that works across all jurisdictions. Focus on identifying and recording the human creative contribution at each stage of the AI-assisted inventive process.

The UK's "highly sophisticated tool" language creates a positive framework for AI-assisted inventions. When advising clients, frame AI as a tool the human inventor used, not as an independent creative agent. The human selected the problem, configured the AI, evaluated its output, and chose the inventive solution. This framing preserves patentability while respecting the human inventorship requirement.

For IP counsel advising AI companies, the Thaler decisions across jurisdictions don't eliminate the ability to patent AI-related innovations. They eliminate the ability to name AI as the inventor. The AI system itself can still be patented (as a method or apparatus) by its human creators. And inventions made using AI as a tool can be patented by the humans who directed the process. The key is structuring the inventorship narrative correctly from the outset.

The Bottom Line

The UK Supreme Court joined the global consensus that AI can't be an inventor. But its "highly sophisticated tool" language gave patent attorneys a clearer framework for claiming human inventorship in AI-assisted inventions than any U.S. court has provided.