According to G 6/91, the entitlement to the fee reduction only exists if the essential element of the act in question is filed in the admissible non-EPO language. In the case of the filing of the European application, the presence of a description is necessary for the accordance of a date of filing (Rule 40(1)(c)), but claims are no longer required for this. According to J 4/88, only the description and claims needed to be in this language to qualify for the fee reduction (not the Request for grant for example). However, since claims are no longer required for a date of filing, the essential element is now the description.
Consequently, the filing fee is reduced if the European patent application (i.e. at least the description) is filed in an admissible non-EPO language (i.e. an official language of a Contracting State which is not an official language of the EPO). The reduction only applies when the application is filed by a resident or national of a Contracting State having this language as an official language. For example, a national and resident of Mexico filing a European application in Spanish does not qualify for a fee reduction, nor does an applicant filing in Japanese, regardless of his nationality or residence.
Where the application is filed by reference to a previously filed application (see A-II, 18.104.22.168), and the previously filed application referred to, is in an admissible non-EPO language and the applicant satisfies the residency and/or nationality criteria mentioned above, then the applicant is also entitled to the reduction in the filing fee. For the purposes of the reduction, it does not matter whether or not the applicant requested that the claims of the previously filed application take the place of the claims in the application as filed (see above).
Since the additional fee which is payable if the application comprises more than thirty-five pages forms part of the filing fee, the reduction applies also to it.
The reduction of the filing fee is also applicable to divisional applications if the parent application was filed in an admissible non-EPO language (see A-IV, 1.3.3, and A-X, 9.2.1) and the divisional application is filed in the same admissible non-EPO language as the earlier application (Rule 36(2) and Rule 6(3)), provided that the other requirements for the reduction are met (see above) and a translation is filed in time (see A-X, 9.2.1).