5.2.1 Filing fee and search fee 

The filing and search fees are due on the day the European patent application is filed. They must be paid either within one month of that date (Rule 38(1), Rule 17(2), Rule 36(3)) or, for Euro-PCT applications, within 31 months of the filing date or, where applicable, of the earliest priority claimed (Rule 159(1)(c) and (e)). Where fees are paid before expiry of the 31-month period and early processing is not explicitly requested (see E‑IX, 2.8), they will be retained by the EPO on the assumption that the applicant indeed wishes to pursue the European-phase processing of the application on expiry of the 31-month period (see A‑III, 13.1). For the additional fees payable as part of the filing fee, see A‑III, 13.2 and A‑IV, 1.4.1.1.