the patent lapses. China No annuity (maintenance) fees need to be paid while applications are pending. Once granted of the patent maintenance fees are due based on the anniversary of application date. The unpaid fees while the patent was pending have to be paid on grant. European Patent Office Renewal fees are payable to the European Patent Office in respect of pending European patent applications in respect of the third year from the date of filing. These fees are paid in advance of the year in which they are due (such that the renewal fee for the third year falls due two years from the date of filing) and fall due on the last day of the month containing the anniversary of the date of filing. Renewal fees may not be validly paid more than three months before they fall due, except for the third renewal fee which can be paid up to six months before its due date (in accordance with amended Rule 51(1) EPC in force since April 2018). If the payment of a renewal fee for a European patent application is not made in due time, the renewal fee may still be validly paid within 6 months of the due date, provided that the additional fee provided by is paid within the 6 months as well. For the calculation of the 6-month additional period, the so-called de ultimo ad ultimo rule is applied by the EPO. According to this rule, the six-month period runs "from the last day of the month to the last day of the month". For instance, if a renewal fee was due in February 2004, the additional fee fell due on August 31, 2004 (Tuesday), i.e. 6 months from the end of February 2004. The obligation to pay renewal fees terminates with the payment of the renewal fee due in respect of the year in which the mention of the grant of the European patent is published. Subsequently, renewal fees are payable to the national offices of the EPC Contracting States in which the European patent is brought into effect. Each Contracting State then pays the European Patent Organisation a proportion of each renewal fee received for a European patent in that State. Whereas for a pending European patent application an applicant must pay a single maintenance fee at the EPO, it may be much more costly to pay several maintenance fees to