The UK Supreme Court has handed down its much-anticipated judgment in Emotional Perception AI v Comptroller General of Patents [2026] UKSC 3 on the patentability of artificial neural networks. This landmark decision overhauls decades of UK case law and aligns the UK’s approach to computer-implemented inventions with that of the European Patent Office (EPO), abandoning the long-established Aerotel test.
Background
Artificial neural networks (ANNs) are a core AI technology, underlying many of the recent breakthroughs in machine learning. Emotional Perception AI (EPAI) sought a patent for a system using a trained ANN to provide media file recommendations based on human emotions rather than traditional genre classifications.
The UK Intellectual Property Office (UKIPO) initially rejected EPAI’s application on the basis that the invention was a computer program “as such” and therefore not patentable under Section 1(2)(c) Patents Act 1977. The UK High Court then overturned the UKIPO’s decision, holding that an ANN is not a computer program and, even if it were, EPAI’s ANN had sufficient technical effect to escape the exclusion (see our blog post here). This was reversed by the Court of Appeal in July 2024 (see our blog post here), which found that the exclusion for computer programs was engaged by ANNs, and that EPAI’s invention did not provide a sufficient technical contribution, and so was not patentable. EPAI appealed to the Supreme Court.
Notably, the Chartered Institute of Patent Attorneys and the IP Federation jointly filed an intervention in this case, demonstrating its practical and commercial significance.
Decision
The Supreme Court considered the following key issues.
- Should Aerotel be abandoned?
Prior to the Supreme Court’s judgment, UK courts have applied the Court of Appeal’s guidance in Aerotel1 when assessing the patentability exclusion for computer programs “as such”. Aerotel advocated a four-step approach: (i) properly construe the claim; (ii) identify the actual contribution; (iii) ask whether it falls solely within the excluded subject matter; (iv) check whether the actual or alleged contribution is technical in nature. However, Aerotel was decided before the European Patent Office had settled its approach to the same issue and the Aerotel judgment expressly acknowledged that it might need to be reconsidered after such event.
The Supreme Court has now unanimously concluded that Aerotel should be abandoned, as it had been firmly rejected by the Enlarged Board of Appeal of the EPO in G1/192 on the basis (with which the Supreme Court broadly agreed) that it had misinterpreted the European Patent Convention.
While the UK courts are not strictly bound by the decisions of the Boards of Appeal of the EPO, they should follow the settled decisions of the Enlarged Board of Appeal unless convinced that they are wrong or “beyond the ambit of reasonable difference of opinion”. This is for reasons of good policy. As many UK patents are obtained via European patent applications processed through the EPO, a consistent approach between the UK and EPO provides critical legal certainty for applicants.
The UK will now apply the approach endorsed by the EPO in G1/19. That requires the question whether the claim discloses an “invention” to be considered first, ahead of and separately from the other three conditions of novelty, inventive step and industrial application. Importantly, under this approach a claim directed to a computer-implemented invention avoids the exclusion for computer programs “as such” merely by referring to the use of a computer or other technical means (the EPO’s so-called “any hardware” approach). However, there is then an “intermediate step” where the claim must be construed to determine which features contribute to the technical character of the invention. This intermediate step filters out features that do not contribute to the technical character of the invention viewed as a whole, ensuring that only features contributing to technical character are considered when assessing novelty and inventive step.
The Court confirmed that the Pozzoli method for assessing inventive step remains valid, though application of the G1/19 test requires that non-technical features be excluded from the assessment.
1 Aerotel Ltd v Telco Holdings Ltd [2006] EWCA Civ 1371.
2 Bentley Systems (UK) Ltd/Pedestrian Simulation (Decisions G1/19) [2021] EPOR 30.
2. Is an ANN a ”program for a computer”?
The Supreme Court concluded that ANNs are programs for computers within the meaning of the legislation, but for different reasons than those given by the Court of Appeal. The Supreme Court rejected the characterisation of an ANN as a physical machine, concluding instead that an ANN is an abstract entity, not a physical object, describing it 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”. Ultimately, an ANN is a set of instructions to manipulate data in a particular way to produce a desired result and so, viewed as a whole, an ANN is a program for a computer.
3. Is the entire subject matter of the claims excluded?
Having concluded that ANNs are computer programs, the Supreme Court needed to consider whether the entire subject matter of EPAI’s patent claims falls within the scope of the exclusion for computer programs “as such”, or whether it includes technical features and so qualifies as an “invention”.
Applying the EPO’s “any hardware approach”, the Court held that EPAI’s claims are not excluded as a computer program “as such”. Although the claimed method involves an ANN which is a program for a computer, it also involves technical means because the ANN can only be implemented on some form of computer hardware, and the claims also refer to a database, communications network and user device. That is sufficient to show that the subject matter of the claims has technical character and is not to a computer program “as such”.
Following the guidance in G1/19, the next stage would be the “intermediate step”, requiring the dissection of the invention into its component features to determine which features contribute to the technical character of the invention as a whole. Non-technical features “as such” (those which do not interact with the technical subject matter of the claim) are to be ignored in assessing novelty and inventive step.
However, the Supreme Court has sent the case back to the UKIPO to make that assessment, noting that it would not be appropriate to make those findings itself and, in so doing, create binding precedent, without the benefit of in-depth legal argument and the views of the UKIPO and specialist judges in the lower courts.
Comment
This is a landmark judgment that fundamentally reshapes UK patent law for computer-implemented inventions, representing the first time the UK Supreme Court has directly addressed the exclusion from patentability for computer programs “as such”. The decision brings the UK into alignment with the EPO after two decades of divergence, providing much-needed legal certainty for innovators and creating a more stable foundation for AI innovation and investment in the UK.
Patent applications for computer-implemented inventions now avoid the patentability exclusion for computer programs “as such” merely by referring to the use of hardware or other technical means. From a practical perspective, this means far more applications will clear the initial “is it an invention?” hurdle and progress to substantive examination and prior art searching rather than being rejected outright as excluded subject matter. However, while the threshold for being an “invention” is much lower, the real battleground has now shifted to the so-called “intermediate step”, where rigorous scrutiny of which features contribute to technical character will determine what can be considered when assessing inventive step.
The Supreme Court declined to apply the intermediate step test to Emotional Perception’s application, instead remitting this task to the UKIPO. Without a body of UK case law or detailed guidance to draw upon, this may create a period of uncertainty as the new test is applied and considered by the UKIPO and lower courts. The Supreme Court recognised that UKIPO personnel and most patent lawyers in the UK have been trained to apply the Aerotel methodology and will need guidance on the new approach. However, practitioners can draw on the extensive body of EPO case law, including the COMVIK approach for mixed technical/non-technical inventions, to guide them through this interim period.
Overall, this is good news for AI innovators. While they will still need to demonstrate that their inventions involve an inventive step over the prior art, they will no longer face the significant risk and cost of having their patent applications rejected at the preliminary stage on the basis that ANNs and other AI technologies are excluded from patentability as computer programs “as such”. The alignment with EPO practice means that UK patents obtained via the EPO, as well as direct UK filings, will all be assessed on a consistent and harmonised basis.
For further information, please contact:
Yohan Liyanage, Partner, Linklaters
yohan.liyanage@linklaters.com
