On 1 April 2026, the European Patent Office’s updated Guidelines for Examination (the guidelines) came into force.

The guidelines are updated annually to reflect the latest legal and procedural developments. While these updates do not represent changes in substantive law, each may affect how applicants draft, file and prosecute European patent applications. We discuss five key changes below.

1. Colour drawings are now permitted

Applicants may now file drawings in greyscale or colour. Such drawings filed on or after 1 October 2025 will be published in this format. This is a departure from previous practice whereby it was only allowable to file black and white line drawings.

However, when filing missing drawings, drawings in translations, and drawings to overcome deficiencies notified by the Receiving Section, they must be in the same format as the original drawings. Therefore, if the original drawings were filed as black and white line drawings, it is not allowable to introduce greyscale or colour.

It is also worth noting that whilst the EPO now accept greyscale and colour drawings, this is not the case in many other jurisdictions including the UK.

Applicants should therefore use colour or greyscale only where it adds real explanatory value, bearing in mind those other jurisdictions that may still require black and white line drawings. Maintaining a consistent drawing format across filings may help reduce the risk of added matter objections or other formal issues later.

2. Use of Artificial Intelligence (AI) tools by the EPO

The guidelines (General Part, Section 5) have been updated to note that parties are responsible for the content of their patent applications and submissions to the EPO regardless of whether such documents have been prepared with the assistance of AI.

It is also noted that AI can improve the quality and efficiency of the EPO and may support its work in many areas. One such area is in the preparation of minutes as outlined below.

Previously, sound recordings in proceedings were made only where evidence was taken. However, in the updated guidelines (Part E-III, 10.1), oral proceedings held by videoconference before the Receiving Section, Examining Division, Opposition Division and Legal Division may now be recorded by the EPO. The audio recordings may be used for the purpose of preparing minutes of the oral proceedings with the assistance of AI.

The recordings will be deleted once the minutes have been issued to the parties to the proceedings. Copies of the recordings will not be made available to the parties.

AI does not reduce the parties’ responsibility for accuracy, so human review remains essential to check submissions generated or assisted by AI for technical and legal accuracy. During oral proceedings, parties should take their own notes which may be cross-referenced and used to verify that all submissions and issues raised are accurately captured in the meeting minutes.

3. Assessment of novelty amended to reflect decision in G1/23

In line with the Enlarged Board of Appeal decision in G1/23, the guidelines (Part G-IV, 2) have been updated to reflect that ‘a product put on the market before the date of filing of a European patent application cannot be excluded from the state of the art …for the sole reason that its composition or internal structure could not be analysed and reproduced by the skilled person before that date.’

In effect, this amendment clarifies that, for products put on the market, a prior disclosure is not excluded from the state of the art solely because the skilled person could not analyse and reproduce the product before the filing date. Instead, the guidelines note that the requirement of enablement is inherently fulfilled as it is ‘satisfied by the skilled person’s ability to obtain and possess the marketed product’.

Technical information about such products which was made available to the public before the filing date forms part of the state of the art irrespective of whether the skilled person could analyse and reproduce the product and its composition or internal structure before that date.

This change is particularly relevant to applicants whose products are commercially available before filing but are difficult to reverse engineer, because such products may now be more readily citable as prior art against later-filed applications.

4. Claim interpretation amended to reflect decision in G1/24

In line with the Enlarged Board of Appeal decision in G1/24, the guidelines (Part F-IV, 4.2) have been updated to confirm that ‘the claims are the starting point and the basis for assessing the patentability of an invention’ and, ‘the description and any drawings are always referred to when interpreting the claims, and not just in the case of a lack of clarity or ambiguity’.

Furthermore, if the description provides a ‘special broad definition’ of a term, the claim must be interpreted in light of that broad definition when assessing patentability.

However, the guidelines also clarify that it is not possible to rely on the description and drawings to read into the claim a restrictive feature when such a feature is not suggested by the wording of the claim. This preserves the fundamental principle that the invention is defined by the claims.

This amendment should go some way in unifying the EPO’s approach with the approach taken by the UPC and national courts, helping to improve legal certainty for parties. In practice, applicants should ensure that the description supports the intended claim scope without introducing wording that could unintentionally broaden or restrict how key claim terms are interpreted.

5. Examiners discretion to admit amendments

During prosecution of the European patent application, amendments may be made of the applicant’s own volition once after receipt of the search report. Any further amendments are made at the discretion of the examiner.

The guidelines (Part H-II 2.3) have been amended to clarify that when the examining division exercises its discretionary power not to admit amendments, they must provide a reason as to why the amended claims are prima facie not allowable.

Additionally, the guidelines note that providing extensive reasoning as to why the amended claims are unallowable is incompatible with a prima facie assessment. In particular, if the reasons for refusal of an amendment must be discussed in the same level of detail as if the amendments had been submitted, the amendments should be submitted.

This change underlines the importance of submitting well-founded amendments as early as possible, since later amendments may still be refused if they are not prima facie allowable.

Of course, the practical impact of these changes will depend on the facts of the case, but applicants should keep them in mind when drafting, filing and prosecuting European patent applications.

If you have any questions about the updated guidelines or for any other intellectual property query, please contact one of our team.

This article was written by Sarah Doyle, if you have any questions about the updated guidelines, please contact sarah.doyle@wilsongunn.com or your usual Wilson Gunn attorney.