Search

We aim to provide complete and accurate search reports and written opinions in a consistent, harmonised manner so the applicants can make the right decisions about their patent applications. 

Complete and accurate searches and written opinions

Our examiners have access to the largest database of prior art in the world, with billions of technical records dating back to 1782. Our collection is constantly growing and helps us deliver a comprehensive search of the highest quality.

The world’s largest prior art collection

Figure: The EPO's prior art collection at a glance

In 2024 the EPO cited Asian-origin prior art in 51.8% of its search reports.

Figure: Asian prior art in EPO search reports 

An Asian-origin citation is a patent document either in Chinese, Japanese or Korean or with a priority document in one of these languages; an Asian-only citation is a Chinese-language, Japanese- language or Korean-language patent document that does not have any patent family member in an EPO language (English, French or German).
An XYE-category citation is a document which, in relation to one or more independent claims, is: novelty- or inventive step-destroying when taken alone (X category); inventive step-destroying when combined with one or more documents of the same category (Y category); a potentially conflicting patent document regarding the filing or priority date (E category).

27.8% of EPO search reports contained at least one non-patent literature (NPL) citation in 2024.

Figure: Percentage of EPO search reports containing one or more NPL citations 

4.7% of EPO search reports contained at least one standards document in 2024. The observed decrease in search reports containing standards in 2023 is largely explained by 25% fewer Euro-PCT with supplementary searches being performed, as such applications tend to have an above-average share of standards citations.

Figure: Percentage of EPO search reports with one or more standards citations

Collaborative Patent Classification

The EPO uses the Cooperative Patent Classification (CPC) scheme, the world's leading standard classification system, which celebrates its tenth anniversary in 2023.

• Currently used by 38 offices
• Independent of language, enabling EPO examiners to find relevant prior art in Asian languages, for example

Independent quality audits

In response to user feedback and pursuing continuous improvement, the EPO has been implementing an extended search audit since October 2021. In this new approach, auditors take an in-depth look at the written opinion in addition to the search report. The search audit results' bar charts provide a transparent overview of the types of findings relating to clarity and sufficient disclosure of the invention, which are now displayed in separate categories. This provides us with more information which can be used to improve our searches and written opinions.

Figure: Search: quality audit findings ​​​​

A consistent and predictable approach  

We consistently perform thorough searches and cite high volumes of relevant prior art helping our applicants make informed and timely decisions. In 2024, 83.7% of EPO search reports identified at least one document that was prejudicial to the novelty or inventive step of one or more of the application's claims. Our search reports have remained remarkably consistent in citing these large volumes of relevant citations over the years.

Figure: Searches with at least one relevant citation and searches with only A-category citations

We consistently provide thorough written opinions: 92.9 % of written opinions raised at least one objection in 2024.

Figure: Negative search opinions

Delivering complete searches and written opinions on time

Timeliness is important to our users. Mean search timeliness for standard searches (i.e. excluding non-unity, unclear and incomplete cases), was 5.5 months.

Figure: Search timeliness 2018-2024

User satisfaction survey

Our regular independent user satisfaction survey shows high levels of satisfaction with our search products. In our 2022/2023 survey, 80% of respondents were satisfied or very satisfied with the EPO's performance in this area.

Figure: User satisfaction survey results for search and written opinions
- SR stands for search report, WO means written opinion.
- Arrows indicate statistically significant changes.

The results of the 2024/2025 USS will be published in Autumn 2025.