UK Supreme Court delivers landmark Emotional Perception AI judgment

11 February 2026 – In a pivotal ruling for the patentability of AI‑related inventions, the UK Supreme Court has overturned the Court of Appeal and held that Emotional Perception AI Ltd’s artificial neural network–based recommendation system is not excluded as a “program for a computer, as such”.

 

This decision in Emotional Perception AI v Comptroller General [2026] UKSC 3 not only resolves the status of the specific invention but also fundamentally reshapes the UK’s approach to computer‑implemented inventions by abandoning the long‑standing Aerotel framework and adopting the European Patent Office (EPO) framework following G1/19, including the principles established in Comvik (T 641/00).

 

Background: From UKIPO to the Supreme Court

Emotional Perception AI Ltd sought to patent a system that uses an artificial neural network (ANN) trained to replicate human emotional or semantic perception of similarity between media files, but using only their objectively measurable properties.

 

The UKIPO initially refused the application on the ground that it constituted a computer program as suchunder Section 1(2)(c) of the Patents Act 1977. The High Court then overturned the UKIPO, holding that an ANN was not a computer program. The Court of Appeal reversed the High Court’s Decision, finding that an ANN was a computer program and therefore excluded. Emotional Perception AI appealed to the Supreme Court and the case was heard in July 2025. Judgment has now been delivered.

 

Crucially, the appeal invited the Supreme Court to consider whether the UK should continue to apply the Aerotel test or instead realign with the EPO’s Enlarged Board of Appeal following G1/19.

 

The Invention: ANN‑Based Emotional Similarity Mapping

During a training phase, the ANN processes pairs of files with two independently derived “distances”: a semantic distance generated by natural‑language descriptions interpreted by a separate natural language processing ANN, and a physical‑property distance based on measurable attributes (e.g., tempo, tone, rhythm). The ANN is trained to align physical distances with semantic ones.

 

After training, during a recommendation phase, the ANN generates “property vectors” for new target files. These are compared with vectors stored in a database to identify files expected to elicit a similar human emotional response.

 

The system is envisaged to be used for recommending music, videos, images, or text content, and is intended to offer faster and more accurate emotional‑similarity recommendations than existing services.

 

Key Legal Issues Before the Supreme Court

Issue 1 – Should the Aerotel approach be abandoned?

Before today, UK law relied on the Aerotel test, a four‑stage framework developed by the Court of Appeal in 2006. The required determining what the claim actually contributed and then assess whether that contribution was excluded subject matter and whether it possessed the necessary technical character. This structured approach effectively governed how computer‑implemented inventions were filtered for eligibility.

 

When ANNs were analysed through this framework, they failed because the “contribution” was classified as nothing more than a computer program implementing a mathematical method, without adding anything considered “technical.”

 

The Supreme Court held that the UK should no longer follow the Aerotel four‑step test, as it is incompatible with the Article 52 of the European Patent Convention and has been expressly rejected by the EPO’s Enlarged Board in G1/19.

 

Instead, the Court adopted the Duns principles (T154/04) and the “any hardware” approach endorsed by the Enlarged Board, while emphasising that the UK does not need to adopt the EPO’s “problem‑solution” approach for assessing inventive step.

 

The Enlarged Board succinctly stated in G1/19 that “A method involving technical means is an invention within the meaning of Art 52(1) EPC”. Put another way, if an invention includes any hardware (such as a computer), it is eligible for patent protection.

 

The Supreme Court accepted the Enlarged Board’s finding that, because the “any hardware” test makes it easy to satisfy the requirement of being an invention, an intermediate filtering step is needed. This step is drawn from the EPO’s Comvik  approach (T641/00) and determines which claim features genuinely contribute to the invention’s technical character, and therefore may be taken into account when assessing inventive step

 

Issue 2 – Is an ANN a “program for a computer”?

The Court confirmed that an ANN, whether implemented in hardware or software, is a program for a computer. An ANN is an abstract computational model that represents a set of instructions for a computer (regardless of hardware choice), including its topology, activation functions, and weight/bias parameters. These collectively amount to a computer program under Article 52(2)(c) EPC.

 

This rejects the High Court’s view that ANNs are not computer programs.

 

Issue 3 – Is the claimed invention a computer program “as such”?

Even though the ANN is a computer program, the invention is not excluded from patentability because the claims involve technical means, including the ANN being implemented on computer hardware.

 

Under the “any hardware” approach, this is sufficient to confer technical character, meaning the invention passes the Article 52 EPC threshold and must now be assessed for novelty and inventive step.

 

The Supreme Court’s Decision

Appeal allowed. UKIPO refusal set aside.

 

The Court held:

1. Aerotel is no longer to be followed in UK law.
2. The approach in G1/19 (minus problem–solution) is now the correct framework for determining whether something is an “invention”.
3. An ANN is a “program for a computer” because it is a set of instructions for a machine to process data, but …
4. The claimed invention is not a program for a computer as such because it involves technical means and therefore is not excluded from patentability.
5. The case is remitted to the UKIPO to examine novelty and inventive step under the new legal framework.

 

Significance for UK Patent Law and AI

This is the most important UK decision on computer‑implemented inventions in two decades. Its implications include:

• Alignment with EPO jurisprudence on Article 52 for the first time since Aerotel.
• A lower threshold for “invention” via the “any hardware” test.
• Increased focus on the “intermediate step”: identifying which features contribute to the invention’s technical character before assessing inventive step.
• Increased clarity for applicants seeking protection for AI and machine‑learning inventions, many of which rely on ANNs.

 

The judgment materially widens the scope for patentability, ensuring that AI‑based and other computer‑implemented inventions are no longer halted at eligibility, but instead proceed to assessment on genuine technical merit.

 

Page White Farrer has a dedicated team specialising in AI‑related inventions. Please contact Thomas Mahon if you have any questions about this judgment or its implications for your IP strategy.

 

This briefing is for general information purposes only and should not be used as a substitute for legal advice relating to your particular circumstances. We can discuss specific issues and facts on an individual basis. Please note that the law may have changed since the day this was first published in February 2026.