2. Language of the proceedings 

If an international application is filed with the receiving Office in one of the EPO official languages, that language will be the language of the proceedings before the EPO and may not be changed either during the international phase or on entry into the European phase (G 4/08).

If the international application is not filed with the receiving Office in one of the EPO official languages, the language of the proceedings before the EPO as International Authority will be the language of the translation furnished for the purposes of the search or, as the case may be, for the international preliminary examination. The following sections provide more detail on the requirement to file a translation.