2.1 The EPO as designated Office by default

The proceedings for the grant of a national/regional patent before a national/regional office can only start if the applicant designated that national/regional office at the time of filing the international application. PCT applicants do not have to designate the PCT contracting states for which they wish to file the international application, because both national and, where possible, regional designations of all PCT contracting states are implied in the PCT request (“automatic designation”) (Rule 4.9(a)(i) and (iii) PCT). This means that, on receipt of the PCT request, the EPO is a designated Office by default, and that every international application is therefore automatically a "Euro-PCT application", i.e. an international application that has the effect of a Euro-direct application as from the filing date. Accordingly, the proceedings for the grant of a European patent may, in principle, be started at any time after the date of filing (Art. 11(3) PCT) (A‑XII, 3.1 and 3.2).

However, if at the time the applicant enters the European phase the designation of all EPC contracting states for a European patent has been withdrawn, the EPO is no longer a designated Office and cannot start acting as a designated/elected Office, because the international application is no longer a Euro-PCT application under Art. 11(3) PCT. In the rare case where only some EPC contracting states have been withdrawn, the EPO can still act as a designated/elected Office for all EPC contracting states that have not been withdrawn.

Since, at present, all EPC contracting states are also contracting states to the PCT, the EPO is by default a "designated Office" for an international application filed under the PCT in respect of all PCT contracting states that were also contracting states to the EPC at the filing date of the international application (OJ EPO 2014, A33; OJ EPO 2023, A79).