AI is a hot topic, particularly in the area of patent law and inventorship.

On Tuesday 21 September 2021, the UK Court of Appeal ruled that artificial intelligence (AI) cannot be listed as an inventor on a patent application (Thaler v Comptroller General of Patents Trade Marks and Designs [2021] EWCA Civ 1374).


The present case related to two patent applications submitted to the UK Intellectual Property Office (IPO) by Dr Stephen Thaler. Both applications listed the inventor as ‘DABUS’, an AI machine built for the purpose of inventing, which had successfully come up with two patentable inventions. The UK IPO had refused to process either application (considering them withdrawn) as they failed to comply with the requirement to list an inventor and Dr Thaler was not entitled to apply for the patents. According to the Patents Act 1977, an inventor must be a ‘person’.

At the Court of First Instance, Mr. Justice Marcus Smith had upheld the IPO’s decision.


On appeal three key issues were considered:

  1. Does an “inventor” have to be a “person”?: The Patents Act 1977 defines an inventor as the “actual deviser” of the invention. The Court of Appeal unanimously held that the 1977 Act was drafted on the basis that an “inventor” had to be a “person” to be an actual deviser. As such, AI machine is not currently recognised by the UK patent system, even if it created the invention.
  2. Was Dr Thaler entitled to apply for a patent for an invention created by the AI machine?: An applicant who is not the inventor must be able to point to an entitlement to apply for a patent in respect of the invention. Dr Thaler argued that as owner of AI machine, he was entitled to the property in any of DABUS’ inventions. Lord Justice Arnold held that as a matter of law this is incorrect, holding that this rule only applied to tangible property and there was no principle of law that an intangible property right (such as intellectual property) created by a person’s property is owned by that person.
  3. Did the UK IPO respond correctly by rejecting the patent application?: As Dr Thaler did not identify a person as the inventor, and failed to identify the derivation of his right to be granted the patent (he simply asserted that it was sufficient that he owned the AI machine), the ICO and the judge at First Instance were correct to reject the patent application.

The appeal was dismissed.

However, although the Court ultimately agreed with the IPO, the decision was split 2-1. Lord Justice Arnold and Lady Justice Laing agreed that the IPO was justified in its decision not to process Dr Thaler’s patent applications, while Lord Justice Birss was in the minority, stating that ‘the fact that the creator of the inventions in this case was a machine is no impediment to patents being granted to this applicant’.

The full judgment can be accessed here.


Dr Thaler is arguing his ‘test’ case across several jurisdictions. The UK Court of Appeal decision differs from a decision handed down in July by the Australian Federal Court, which recognised DABUS as the inventor and allowed Dr Thaler’s patent application. In South Africa, the patent application was also granted with DABUS listed as the inventor. The European Patent Office (EPO), however, has rejected Dr Thaler’s arguments.

The position on AI inventorship globally is far from aligned, but for the time being the UK has made its position clear. It will be interesting to see if this case is appealed to the UK Supreme Court, and if so, whether the UK government takes the opportunity to make legislative changes to the Patents Act 1977.

AI and the UK government

AI and AI generated inventions are already firmly on the UK government’s radar. In March of this year, the government published its response to its 2020 call for views on AI and intellectual property and, on Wednesday 22 September, published its National AI Strategy with a view to making Britain a global AI superpower. AI is also due to be the subject of further government consultation later this year.