Background
The appeal concerned a patent application by Emotional Perception AI Ltd for a system using an artificial neural network (“ANN”) to recommend media files such as music, videos, or text, based on their emotional similarity. The ANN is trained through machine learning to compare user‑selected files with other files that produce a similar emotional response, enabling more relevant, personalised recommendations.
The UK Intellectual Property Office (“UKIPO”) initially rejected the application, relying on Article 52(2)(c) of the European Patent Convention (“EPC”) and section 1(2)(c) of the Patents Act 1977, which exclude “programs for computers… as such” from patentability. Although the High Court overturned the refusal, the Court of Appeal reinstated it by applying the long‑established four‑step test from Aerotel Ltd v Telco Holdings Ltd [2006] EWCA Civ 1371.
Judgment
The appeal to the Supreme Court raised three issues.
Issue 1: Should the Aerotel Framework Be Abandoned?
The Supreme Court held unanimously that Aerotel should no longer be followed. For two decades, UK courts applied Aerotel to determine whether a claimed invention made a “technical contribution” beyond excluded subject matter. However, the EPO has long rejected this approach. In Duns Licensing Associates [2004], the EPO endorsed an “any hardware” approach, under which a claim is not excluded under Article 52(2) EPC if it involves any physical hardware, however basic.
The Court also relied on the EPO Enlarged Board’s endorsement of this approach in Bentley Systems (UK) Ltd/Pedestrian Simulation (Decision G1/19) [2021] (“G1/19”). UK courts are not strictly bound by EPO decisions, but should follow them “unless convinced that they are wrong or beyond the ambit of reasonable difference of opinion”. The Supreme Court concluded that Aerotel incorrectly conflated the concept of an “invention” with separate patentability requirements such as novelty and inventive step. The correct approach is to determine first whether a claim has “technical character”- a threshold easily met where any technical means are present.
Issue 2: Is an ANN a “Program for a Computer”?
The Court held that an ANN falls within the meaning of a “program for a computer” under Article 52(2)(c). Although inspired by biological neural structures, ANNs operate by applying mathematical operations to numerical data and can be implemented across various hardware types. They therefore constitute sets of instructions to a machine—consistent with the definition of a computer program.
This conclusion, however, did not determine the outcome.
Issue 3: Is the Entire Claim Excluded?
Despite holding that an ANN is a computer program, the Court ruled that the claimed invention was not excluded as a “program for a computer… as such”. Applying the “any hardware” test, the Court found that the invention necessarily involves technical means—namely, computer hardware that implements the ANN. This provides the required technical character under Article 52(1) EPC, meaning the invention qualifies as an “invention” and is not excluded at the threshold stage.
The UKIPO was therefore wrong to refuse the application solely on exclusion grounds.
Intermediate Step
The Court also identified an “intermediate step” between clearing the "as such" exclusion in respect of programs for computers, and establishing an inventive step, requiring decision‑makers to disregard features that do not contribute to the invention’s technical character. Having cleared the low Article 52 threshold, the application was remitted to the UKIPO to apply this step before assessing novelty and inventive step.
Whether the Supreme Court's judgment will lead to a profusion of successful patent applications in respect of a wide class of software programs requiring some element of hardware to function, is likely to depend on the subsequent approach by the courts to this "intermediate step". ANNs are distinct from many software programs in the extent to which their functionality is dependent on the network design of numerous processing units working in parallel and, as such, the argument that their hardware components are material to their technical character is clear. Could the same be argued of, for example, any software offered as a service through the Cloud, on the basis that it requires chips and servers to operate? Time will tell.
Conclusion
This judgment brings UK patent law back into line with EPO practice, lowers the initial barrier for patenting AI and software‑related inventions, and confirms that while ANNs are computer programs, they are not automatically excluded. Applicants working with AI, software, and data‑driven technologies should consider their UK filing strategies in light of this significant shift, while keeping a close eye on the Courts' and UKIPO's further guidance on the application of the "intermediate step".
If you would like to discuss any points raised in this article, or think your business could be affected, please contact the authors, Sam Hodgson and Imogen Francis.
Thank you to Charlotte Barber and Eirini Sakellari for their contribution to writing this article.
