UK Supreme Court Resets Approach to Patentability of Computer-Implemented Inventions

The UK Supreme Court issued a landmark decision on 11 February 2026, fundamentally shifting the approach to patenting computer-implemented inventions, including those concerning artificial intelligence, in the UK. In doing so, the UKSC unanimously held that the Aerotel four-step test should be abandoned in favour of aligning with the European Patent Office’s approach in G1/19.

KEY TAKEAWAYS

• In Emotional Perception AI Limited v Comptroller General of Patents, Designs and Trade Marks [2026] UKSC 3, the UKSC unanimously confirmed that computer-implemented inventions are not excluded from patentability as a “program for a computer . . . as such” if they involve technical means.
• The present case concerned an artificial intelligence (AI) system which uses an artificial neural network (ANN). This was held by the UKSC to be a “program for a computer” within the meaning of Article 52(2)(c) of the European Patent Convention (EPC).
• The longstanding approach set out in Aerotel was overturned in favour of aligning with the decision of the Enlarged Board of the European Patent Office (EPO) in G1/19, meaning that the assessment of eligibility first involves a low hurdle “any hardware” assessment, and then an “intermediate step” of filtering out features of the invention that do not contribute to the technical character of the invention.
• The UKSC concluded that the present claims satisfy the “any hardware” assessment, however, the application of the “intermediate step” and the subsequent assessment on patentability would be remitted to the Hearing Offer in the UK Intellectual Property Office (UKIPO).

BACKGROUND

Emotional Perception AI Ltd applied for a UK patent covering an ANN trained to examine and measure the similarities and differences between media files in order to make recommendations to a user of other files which are similar in terms of human perception and emotion, regardless of genre.

The Hearing Officer in the UKIPO initially rejected Emotional Perception AI’s patent application, finding the claimed invention was excluded as a “program for a computer . . . as such” under Section 1(2)(c) of the Patents Act 1977 (the source provision for which is Article 52(2)(c) of the EPC). While the High Court allowed Emotional Perception AI’s appeal, the Court of Appeal reinstated the Hearing Officer’s initial decision through applying the Aerotel four-step test which had guided UK law for nearly 20 years.

This prompted Emotional Perception AI’s appeal to the UKSC, raising three key questions: (1) whether the guidance in Aerotel should still be followed, (2) whether an ANN is (or contains) a “program for a computer,” and (3) whether the entire subject matter of the claims is excluded from patentability.

THE UK SUPREME COURT’S DECISION

Abandoning Aerotel in Favour of Alignment with EPO Jurisprudence

Aerotel Ltd v Telco Holdings Ltd [1] set out the following four-step structured approach for determining whether a computer-implemented invention is patentable:

1. Properly construe the claim
2. Identify the actual contribution
3. Ask whether it falls solely within the excluded subject matter
4. Check whether the actual or alleged contribution is actually technical in nature

The Aerotel approach had been rejected by the EPO’s Board of Appeal, [2] however, which prefers an alternative test, starting with asking whether the subject matter of the claim embodies or involves the use of a piece of physical hardware.

If so, it would not be automatically excluded from patentability under Article 52(2)(c) of the EPC as being a computer program as such. This “any hardware” approach has been subsequently approved and elaborated upon by the EPO’s Enlarged Board in G1/19. [3]

The UKSC considered there to be real force in the Enlarged Board’s criticism of Aerotel and concluded that the Aerotel approach (in particular steps 2–4) cannot be maintained.

The UKSC adopted the approach endorsed in G1/19 instead, which can be summarised as follows:

1. First, assess whether the claim amounts to an “invention” within the meaning of Article 52 of the EPC, which is separate from the conditions of novelty, inventive step, and industrial application. This is a low hurdle that can be satisfied by reference to the use of “any hardware.”
2. Second, as an “intermediate step,” establish the features of the claim that contribute to the technical character of the invention. This acts as a filter to ensure that features not contributing to the technical character of the invention are not considered in further patentability analyses.
3. Third, assess novelty and inventive step by reference to the features contributing to the technical character of the invention.

Artificial Neural Networks Are ‘Programs for Computers’

The UKSC endorsed the Hearing Officer’s characterisation of an ANN as “an abstract model which takes a numerical input, applies a series of mathematical operations (applying weights, biases and an activation function) and outputs a numerical result at successive layers,” and subsequently found that an ANN is a “program for a computer” under Article 52(2)(c) of the EPC.

Computer-Implemented Inventions Are Eligible for Patent Protection in the UK

Applying the new test, the UKSC found that it was “beyond dispute” that Emotional Perception AI’s claims are to an “invention” and are therefore not excluded under Article 52(2)(c) of the EPC. This is because although the ANN was found to be a “program for a computer,” it could only be implemented on some form of computer hardware.

However, while the UKSC provided some limited assistance as to how the “intermediate step” should be assessed, it declined to make that assessment in relation to the claims at issue and instead remitted the case back to the Hearing Officer for consideration.

IMPLICATIONS

The UKSC’s judgment has immediate and significant practical implications for businesses and innovators in the AI and software sectors. While the Aerotel test had similarities with the EPO approach, the law in the UK stood apart from that applied in other EPC states and was widely considered to be stricter than in the rest of Europe. Both approaches require a “technical” contribution, but that will now be assessed in the UK as part of a patentability (i.e., novelty and inventive step) analysis as opposed to the eligibility stage.

Companies developing AI-based solutions should be aware that under the new test the reference to technical means in a patent claim (such as to hardware) should be sufficient to overcome the exclusion for computer programs “as such” under UK law. This harmonisation with EPO practice is expected to deliver greater predictability and consistency for patent applicants operating across the UK and Europe, reducing the risk of divergent outcomes.

That being said, applicants must remain mindful that clearing the Article 52 eligibility hurdle is only the first step: the “intermediate step” of proving the technical nature (or otherwise) of a claim still plays a critical role in the assessment of novelty and inventive step.

The UKSC’s decision to remit the case for further consideration by the Hearing Officer in the UKIPO underscores that AI-based inventions, while not categorically excluded, will turn on whether the claimed features which contribute to the technical character of the invention are novel and inventive. It seems inevitable that the UKIPO, when applying the EPO-derived test, will more closely align with EPO outcomes, but the degree to which that happens, and in particular whether software patents in practice become easier to obtain and defend in the UK, is yet to be seen.

LOOKING AHEAD

The UKSC’s decision in Emotional Perception AI marks a pivotal development in the law governing the patentability of computer-implemented inventions, including AI and neural network inventions. By abandoning Aerotel and confirming that computer software claims referencing hardware are not necessarily excluded from patentability, the UKSC provides welcome alignment with the EPO case law.

This decision will be positive news to companies operating within the AI sector of the UK, who should carefully assess how these changes affect their intellectual property strategies going forward.

Paralegal Dania Al-Bayati contributed to this LawFlash.