The international application, i.e. the request, description, claim(s), drawing(s) and abstract, must be filed with the EPO as receiving Office in English, French or German. An international application filed in another language will be forwarded to the IB to act as receiving Office instead of the EPO. This means that there is no possibility to file an application with the EPO as receiving Office in any other language as is provided under Article 14 EPC for European patent applications not filed via the PCT route (Euro-direct applications).

If an application is filed with the EPO as receiving Office in one of its official languages, that language will be the language of the proceedings which may not be changed either during the international phase or on entry into the European phase (see points 5.1.014-points 5.1.015). However, with the exception of amendments and corrections to the application, for which the language of the international application must be used, any other correspondence with the EPO may be in any of the EPO's three official languages.