https://www.epo.org/en/service-support/faq/myepo-services/third-party-observations/general-information/may-i-raise

May I raise objections against an international patent application?

Since 2 July 2012, third parties have been able to submit observations to the International Bureau about prior art in published PCT applications if they believe that the invention claimed lacks either novelty or inventive step. They can do this as from the date of the international publication and up to 28 months from the priority date. They can use WIPO’s ePCT system or the Patentscope search system.

As explained in WIPO's FAQs, observations are transmitted to any competent International Searching Authority, and/or International Preliminary Examining Authority involved in the processing of the application during the international phase, if the International Bureau has not yet received the international search report, supplementary international search report or international preliminary report on patentability (Chapter II of the PCT) respectively. To the extent that the observations are received by those Authorities in time to be taken into account in drawing up their respective reports, any prior art referred to in the observations should be considered, provided that either a copy of the prior art is included, or it is otherwise immediately available to the examiner. The observations are also transmitted to the designated Offices promptly after the expiration of 30 months from the priority date. The designated Offices are, however, not obliged to take them into account during national processing.

For more general information about third-party observations in the international phase, see WIPO's FAQ , or contact WIPO's PCT Information Service as follows:

Telephone: (+41-22) 338 83 38