UK Supreme Court Rewrites AI Patent Law as US Courts Pull in Opposite Direction

The Aerotel Test Dies After Two Decades

On February 11, 2026, the UK Supreme Court handed down Emotional Perception AI Ltd v Comptroller-General of Patents [2026] UKSC 3, fundamentally overhauling how artificial intelligence inventions are assessed for patentability. The decision abandons nearly twenty years of established practice and aligns UK law with the European Patent Office's more permissive approach.

The case concerned a media recommendation system using an artificial neural network (ANN) trained through a specific methodology. The UK Intellectual Property Office had rejected the application as a "program for a computer...as such" under section 1(2)(c) of the Patents Act 1977. After contradictory lower court rulings, the Supreme Court unanimously reversed the refusal.

"Any Hardware" Clears the First Hurdle

The Court adopted the EPO's "any hardware" test, under which claims involving any physical hardware—however mundane—will not be excluded at the initial eligibility stage. This represents a dramatic lowering of the threshold compared to the restrictive four-step Aerotel test that had governed UK practice since 2006.

For the neural network at issue, the Court found that implementation necessarily requires computer hardware. Combined with references to databases, communication networks, and user devices in the claims, this satisfied the technical character requirement. The ANN is "not a computer program as such" because it cannot exist without hardware infrastructure.

But Federal Circuit Moves the Opposite Way

This liberalisation stands in sharp contrast to recent US developments. The Federal Circuit's April 2025 decision in Recentive Analytics v Fox Corp affirmed invalidity of four AI patents, finding that claims merely applying "generic machine learning models to scheduling and programming tasks" failed eligibility under 35 U.S.C. § 101.

The divergence reflects different judicial philosophies. UK courts now focus on whether claims have "technical character"—a low bar requiring only hardware involvement. US courts continue applying the Alice/Mayo framework, demanding concrete technological improvements beyond generic AI applications.

Practical Consequences Still Unclear

While the UK ruling creates easier access to patent protection, significant uncertainty remains. The Supreme Court introduced an "intermediate step" filtering out features that don't contribute to technical character before assessing novelty and inventive step. How the UKIPO will apply this filter in practice remains unknown.

Patent prosecutors are already adapting. Claims now emphasise technical implementation details rather than abstract computational processes. But the gap between what the USPTO grants and what Federal Circuit sustains creates portfolio risks—patents obtained under more receptive examination may still face invalidity challenges under unchanged court doctrine.

Trans-Atlantic Strategy Requires Precision

The UK's alignment with EPO practice eliminates the "legal friction" that previously forced different application strategies for Britain versus continental Europe. Companies can now file substantially similar applications across EPO member states.

But this convenience comes with a caveat. The USPTO's recent guidance under Director John Squires has made examination more accommodating, yet Federal Circuit precedent remains unchanged. Patent applications must satisfy both administrative examination standards and judicial validity requirements—standards that increasingly diverge.

The Supreme Court's ruling establishes the UK as a more welcoming jurisdiction for AI patent protection. Whether this translates to meaningful commercial advantage depends on implementation details still being worked out. One thing is certain: the twenty-year-old Aerotel framework is dead, and with it, a generation of restrictive UK patent practice.