Aerotel: Superseded in February 2026

Historical. The Aerotel four-step approach is no longer followed in the United Kingdom, per Emotional Perception AI Ltd v Comptroller General of Patents [2026] UKSC 3, 11 February 2026. This site has no UK practitioner. Current as of 22 August 2026.

Correction, 22 August 2026. This page previously said the four-step approach remained what UK examiners are directed to. That was wrong when published. The Supreme Court had already held otherwise six months earlier: "our conclusion is that the Aerotel approach should not be followed", and that "the UK should adopt the same interpretation of article 52 as the Enlarged Board" of the EPO. The page is kept as history rather than deleted, because the four steps appear throughout a decade of commentary a reader may encounter.

What it was

From 2006 to 2026 the United Kingdom analysed the exclusions through four steps set out by the Court of Appeal: properly construe the claim, identify the actual contribution, ask whether it falls solely within excluded subject matter, and check whether the contribution is technical in nature.

In 2006 the Court of Appeal disposed of two appeals together and set out that four-step approach. It governed UK practice for two decades, and step two carried the weight: identifying what an invention actually contributes is a judgment rather than a reading.

On 11 February 2026 the Supreme Court departed from it. The Court was candid about the disruption, noting that officers in the UKIPO and most UK patent lawyers "have been trained or become accustomed to applying the Aerotel methodology as a matter of course, and would need to be told what different approach should now be followed."

What replaces it is alignment with Europe. The Court concluded that the UK should adopt the same interpretation of article 52 as the EPO's Enlarged Board of Appeal in G1/19.

The Court also limited how far it went. It said its conclusion "does not in our view require UK courts to change the" whole of their approach, and explained why it "should not venture far" beyond the question in front of it. Departing from Aerotel is settled. Exactly what UK practice looks like in its place is still developing, and a page cannot tell you where it landed.

What This Page Is Not

Do not use the four steps as a current test. They are here so a reader who meets them in older commentary can recognise what they are and when they stopped applying. Running them on an invention today would be applying a method the Supreme Court has set aside.

It does not state current UK practice. It states what was superseded, and when.
It does not say the Supreme Court held AI inventions patentable. Clearing the exclusion is not novelty, inventive step or sufficiency.
It does not say what the UK approach now requires in detail. The Court expressly declined to go far in that direction.
It is UK law and has no application in the United States.

Educational, not legal advice, and this site has no UK practitioner. Anything that matters should go to a UK attorney, and on this topic more than most, because the ground moved recently.

Sources

Emotional Perception AI Ltd v Comptroller General of Patents, Designs and Trade Marks [2026] UKSC 3 (11 February 2026)
Aerotel Ltd v Telco Holdings Ltd; Macrossan's Application [2006] EWCA Civ 1371
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