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The European Patent Office’s Guidelines for Examination are the basis for the implementation of the European Patent Convention.
They provide standard instructions for EPO examiners, ensuring legal consistency and uniform practice throughout the entire patent lifecycle.
Revised annually to reflect case law and evolving practice, they are essential reading for patent attorneys and applicants prosecuting applications through the EPO.
The latest edition came into force on 1 April 2026. This was a significant update, embedding two landmark rulings (G 1/24 and G 1/23).
The guidelines update also involved noteworthy procedural changes, the EPO’s first ever formal guidance on AI and changes to accelerated search under the PACE scheme.
Our European patent specialists have outlined six key developments to be aware of.
1. Mandatory claim interpretation using the description (G 1/24)
The guidelines now state that patent descriptions and drawings must always be used to interpret the claims, even if the claim language seems clear on its own.
Previously, EPO examiners often looked only at the claims themselves unless a term was ambiguous. Now, if the description defines a term in the claims more broadly or narrowly than its ordinary meaning, that definition may influence how the claim is interpreted during both examination and opposition.
While the case law in this area is still developing, it is notable that the first decisions after this change do not always result in the claims being interpreted to align with the description. The Boards of Appeal have, generally, taken the position that whilst the description must be consulted, that doesn’t mean that the consultation must change the interpretation of the claims.
To date, decisions coming from the Board of Appeal after G1/24 have been less favourable to the Patentee, with some notable exceptions (T 1620/23).
To avoid unintended impacts on protection, it is essential that the description and claims of any application are wholly aligned, and their influence on one another are considered, before any application is filed.
2. Marketed products as prior art (G 1/23)
The EPO now considers any product previously placed on the market as part of the prior art, along with all its analysable properties, regardless of whether a competitor could reproduce it.
The old requirement was that a product only counted as prior art if it was ‘enabling’ – that is, a skilled person could reproduce it.
This reproducibility requirement has been scrapped for marketed goods. As such, if your product is publicly available it is now novelty destroying, even if a competitor can’t analyse its composition or structure, or make it themselves from scratch.
This emphasises the importance of filing before any marketing launch.
Read more: G 1/23: EPO confirms a product can still be prior art even if it can’t be reproduced
3. Simpler novelty test for selection inventions
The traditional, complex three-part test for assessing the novelty of a sub-range (a specific numerical or chemical range selected from a broader range already disclosed in the prior art) has been replaced by a more straightforward standard.
The traditional test asked whether the sub-range is narrow enough, sufficiently far removed from the prior art range or not something a skilled person would have seriously contemplated.
The 2026 guidelines replace all of this with the ‘gold standard’. Novelty for a selection is now based on whether the specific sub-range is ‘directly and unambiguously disclosed’ in the prior art. If not, it is new.
This has simplified the legal hurdle, but it means that patent practitioners cannot secure novelty for specific chemical or numerical ranges by relying on the ‘sufficiently far removed’ argument.
4. Formal stance on artificial intelligence
For the first time, the EPO guidelines include a dedicated section on the use of AI in patent proceedings. This clarifies that parties are fully responsible for all AI-assisted or generated content in their filings.
This means that the burden of accuracy is placed on the applicant. If an AI tool hallucinates a technical claim, invents a reference or misrepresents prior art in a submission, the applicant bears the consequences.
The guidelines also note that the EPO can use AI to enhance the quality and efficiency of its work.
5. Acceptance of colour drawings
The EPO now formally allows for the filing of colour drawings and photographs in patent applications.
This represents a significant modernisation step, particularly welcome in fields such as biotech, pharmaceuticals and advanced materials, where greyscale imagery can fail to capture crucial detail.
Be aware, however, that if you file in colour at the EPO but subsequent PCT or other priority claiming filings are in black and white, you may face ‘added subject matter’ or priority entitlement issues. Consistency is key.
6. Abolition of PACE accelerated search
The EPO has discontinued accelerated search under the PACE (Programme for Accelerated Prosecution of European Patent Applications) scheme.
PACE allowed applicants to ask the EPO to prioritise its application, moving it to the front of the queue for search and examination. Whilst accelerated examination still remains available, the search phase has been removed.
This means that patent applicants who relied on PACE to compress their timelines will need to factor this into their filing strategy.
The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.
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