Source: https://www.epo.org/law-practice/legal-texts/html/guidelines2018/e/a_x_5_2_4.htm
Timestamp: 2019-04-22 04:59:01+00:00

Document:
Renewal fees for a European patent application in respect of the coming year are due on the last day of the month containing the anniversary of the date of filing of the European patent application.
According to Rule 51(1) as amended with effect from 1 April 2018 (OJ EPO 2018, A2), the renewal fee in respect of the third year may be paid up to six months before it falls due. All other Renewalrenewal fees may not be validly paid more than three months before they fall due. Examples: if a European application has a filing date in November 2008, according to Rule 51(1) the renewal fee for the third year has a due date of 30 November 2010 and the earliest date for payment is 31 August 2010; if a European application has a filing date in May 2009, according to Rule 51(1) the renewal fee for the third year has a due date of 31 May 2011 and the earliest date for payment is 28 February 2011.
Renewal fee payments made earlier than three months before the due dates permissible prepayment periods are not valid and will be refunded by the EPO, unless made shortly before the permissible prepayment periodthose periods. In this case, however, the payment will only take effect on the first day of the permissible prepayment period.
If the renewal fee has not been validly paid on or before the due date, it may still be validly paid within six months of the said date, provided that the additional fee is paid within this period. The additional fee can be paid until the last day of the sixth month following the month containing the anniversary of the date of filing (see J 4/91, reasons 2.7). This six-month period begins on the last day of the month referred to in Rule 51(1), first sentence, even if the circumstances described in Rule 134(1), (2) and (5) apply. Rule 134 is applicable to the calculation of the expiry of the six-month time limit for payment of the additional fee (see J 4/91, reasons 3.2). Whilst a notice draws the applicant's attention to the possibility under Rule 51(2) and Art. 2(1), item 5, RFees, he may not invoke the omission of such notification (see J 12/84 and J 1/89). For renewal fees for European divisional applications see A‑IV, 1.4.3.
If the applicant requests entry into the regional phase before the expiry of the 31-month period (see Art. 22 PCT and Art. 39 PCT), in order for the request to become effective the renewal fee in respect of the third year has to be paid if the fee has fallen due earlier under Rule 51(1). If the renewal fee is not paid on the date early processing is requested, the request for early processing will be effective only as from the date on which the renewal fee is paid (and all further requirements necessary on the latter date have been complied with).
The obligation to pay renewal fees terminates with the payment of the renewal fee due in respect of the (patent) year in which the mention of the grant of the European patent is published, see Art. 86(2). "Patent years" are calculated as from the date of filing of the application. The first patent year (Art. 86(1), Art. 141(1)) starts on the date of filing and ends on the same date of the following year. For the second and subsequent years, the patent year starts one day after the anniversary of the date of filing and ends on the same day as the date of filing of the following year.
This means that, for the last renewal fee payable to the EPO, it is not the due date but the beginning of the respective patent year that is decisive. If the mention of the grant of the European patent is published on the anniversary of the date of filing, the renewal fee in respect of the next patent year, which has not yet begun, is no longer payable to the EPO but to the national authorities.
Special provisions apply with regard to the due date for renewal fees in respect of cases where there is a successful request for re-establishment of rights under Art. 122 or a successful petition for review of a decision of the board of appeal under Art. 112a.

References: Art. 2
 Art. 22
 Art. 39
 Art. 86
 Art. 141
 Art. 122
 Art. 112