On 1 July 2014, a new Rule 66.1ter and an amended Rule 70.2(f) Patent Cooperation Treaty (PCT) entered into force. Due to these new provisions, the European Patent Office (EPO) in its function as an International Preliminary Examination Authority (IPEA) for Chapter II PCT procedures will conduct a "top-up" search to find prior art that was published or became available after the date on which the international search report was established.

In a notice from the European Patent Office, the following key aspects of this "top-up" search are highlighted:

(i) The EPO will conduct a "top-up" search at the start of the Chapter II PCT procedure, and no express request by the applicant is required in this respect.

(ii) The "top-up" search will mainly focus on finding intermediate prior art documents that have become public since the international search was performed which could become relevant under Article 54(3) European Patent Convention in the European phase. The search will also cover prior art that was cited in national proceedings for the same application if such documents became available to the EPO.

(iii) The "top-up" search will not extend beyond the subject-matter searched by the International Searching Authority.

(iv) As a general rule, a "top-up" search will be conducted for all the claims forming the basis for the procedure under Chapter II PCT. Where the EPO in its function as IPEA considers that the international application does not comply with the requirement of unity of invention, the applicant will first be invited either to restrict the claims or to pay additional fees.

(v) Where the international application is amended and the basis for the amendments is not sufficiently explained or the amendments go beyond the disclosure of the international application as originally filed, the EPO will limit the "top-up" search to the scope of the claims forming the basis of the international preliminary examination report.

(vi) If relevant written documents are found during the "top-up" search that give rise to objections, in particular with regard to novelty and inventive step, the EPO in its function as IPEA will issue a second written opinion or conduct a telephone consultation.

(vii) Any relevant documents found during the "top-up" search will be listed in the international preliminary examination report, with the exception of documents that become irrelevant in view of amendments or arguments filed in reply to the written opinion.

(viii) In the event that only intermediate prior art documents (P) or potentially conflicting applications (E) are found during the "top-up" search and there are no other objections, a second written opinion will only be issued if the documents would give rise to objections under Article 54(3) European Patent Convention in the regional phase before the EPO. Otherwise, an International Preliminary Examination Report will be issued.