If the EPO acts as an International Searching Authority under the terms of Art. 154, it establishes the international search report in accordance with the PCT International Search and Preliminary Examination Guidelines and transmits it to the International Bureau (see Art. 16(1) and 18 PCT). For international applications filed on or after 1 January 2004 the EPO establishes also a ‘'written opinion of the International Searching Authority'' (WO-ISA) (Rule 43bis PCT). The WO-ISA is transmitted to the IB together with the ISR. A copy of the ISR and, if applicable, the WO-ISA, is sent also to the applicant.

There is no possibility for a dialogue between the applicant and the EPO on the International Search Report (ISR) and the WO-ISA. However, in reaction to the ISR and WO-ISA, the applicant may file with the IB amended claims under Article 19 PCT together with a brief statement explaining the amendments and indicating their likely effect on the description and drawings (see IX, 5.7). Further, the applicant may in response to the WO-ISA file ‘'informal comments''. Amendments under Article 19 PCT and informal comments must be sent directly to the International Bureau.

A copy of the international search report is also sent to the applicant who may, as a result, file with the International Bureau amended claims, and may also file a brief statement explaining the amendments and indicating their likely effect on the description and drawings (see IX, 5.7).

With regard to deadlines and procedural steps before the EPO as an International Searching Authority, see the Guide for applicants: "How to get a European patent, Part 2: PCT procedure before the EPO - Euro-PCT", April 2002. A new edition will be published soon. Fundamental changes of the Regulations under the PCT effecting the processing in the international phase entered into force on 1 January 2004. In the new edition only the new procedure, applicable to applications with a filing date on or after 1 January 2004, will be set out. The edition of April 2002, insofar the former procedure in general is set out therein, is still useful for applications with a filing date before 1 January 2004. For applications concerning nucleotide or amino acid sequences, see A-VII, 4.2 and Supplement No. 2 to OJ 11/1998.