Supreme Court Abandons Aerotel Test, Signals New Era for AI Patent Protection

Emotional Perception AI Ltd v Comptroller-General of Patents, UK Supreme Court, 11 February 2026.

What Was Actually Decided

The UK Supreme Court unanimously overturned twenty years of patent law in a single judgment. The Aerotel four-step test, which had governed computer program exclusions since 2006, is gone. In its place: the European Patent Office's "any hardware" approach that sets a dramatically lower threshold for AI and software inventions to clear the initial patentability hurdle.

The case concerned Emotional Perception AI's neural network system for media recommendations. The UKIPO had rejected it as a "program for a computer...as such." The High Court reversed. The Court of Appeal reinstated the rejection. But the Supreme Court didn't just allow the appeal: it rewrote the rules.

"The Aerotel approach should no longer be followed," the Court declared. Instead, if an invention involves any physical hardware, however mundane, it escapes the computer program exclusion. The technical contribution analysis moves to what the Court termed an "intermediate step" that filters out non-technical features before assessing inventive step.

The Practical Impact

For AI companies, this is the difference between early rejection and substantive examination. Under Aerotel, patent examiners could dismiss neural networks as mere software before considering their technical merits. Under the new framework, virtually any AI system implemented on hardware will proceed to full examination.

The UKIPO has already suspended its AI examination guidelines and committed to alignment with EPO practice. Patent applications that would have faced summary rejection eighteen months ago will now receive detailed prior art searches and technical analysis. For startups that had defaulted to expensive European filings to avoid UK hostility to software patents, the calculus has shifted.

But this isn't a carte blanche for AI patents. The Supreme Court deliberately left the "intermediate step" undefined, acknowledging it would be "unwise" to create binding precedent without deeper legal argument. The result is procedural clarity coupled with substantive uncertainty.

Where the Rubber Meets the Road

The new test creates two distinct phases. First, the "any hardware" assessment, essentially automatic for any AI system running on computers, servers, or mobile devices. Second, the intermediate step that determines which claimed features contribute to the invention's "technical character."

Only features that survive this filtering process count toward novelty and inventive step. This shifts the battleground from categorical exclusions to nuanced technical analysis. Patent attorneys will need to emphasise hardware implementation and measurable technical effects while identifying which algorithmic improvements constitute genuine technical contributions.

For now, each AI patent application "will continue to be examined on its individual merits," according to the UKIPO. But without detailed guidance on the intermediate step, examiners and applicants are navigating uncharted territory.

Historical Parallel

This mirrors the EPO's evolution after Vicom (1987) established that computer-implemented inventions could be patentable if they produced technical effects. The subsequent decades saw incremental refinement of what constitutes "technical character": mathematical algorithms remain abstract, but their application to solve concrete technical problems can qualify.

The UK had diverged with Aerotel's emphasis on identifying the "actual contribution" and asking whether it was technical in nature. This often led to abstract analysis divorced from how the invention actually worked. The Supreme Court's alignment with the EPO suggests recognition that modern innovation requires more nuanced treatment than categorical exclusions allow.

What Comes Next

Emotional Perception's case returns to the UKIPO for substantive examination under the new framework. How the hearing officer applies the intermediate step will provide the first indication of how this plays out in practice. Expect detailed technical argument about which neural network features contribute to technical character and which remain algorithmic abstractions.

The UKIPO must also update its Manual of Patent Practice and examination guidelines. Given Director Squires' emphasis on AI-friendly policy, this revision process will likely favour broad interpretation of technical contribution rather than narrow exclusions.

This creates pressure on the broader European system. While UK courts aren't bound by EPO decisions, the Supreme Court's emphatic endorsement of EPO jurisprudence suggests continuing alignment. But divergence remains possible, particularly if the EPO's Enlarged Board revisits these questions.

The next procedural milestone is the UKIPO's updated examination guidelines, expected within six months. For AI companies filing patents now, the message is clear: emphasise technical implementation and measurable effects. The age of categorical software exclusions is ending, but the substantive analysis is just beginning.