I.-The six-month period provided for in the second paragraph of Article L. 612-19, during which payments made after the due date are validated subject to the payment of a late fee, is counted from the day following the due date of the annual fee.
Any payment made after the due date shall be considered valid:
when it relates to a patent application resulting from the division of a patent application, provided that it takes place no later than the last day of the fourth month following the date of receipt of the divisional application documents;
when it supplements an insufficient payment made before the due date, provided that it takes place within the six-month period referred to above.
II.-Payment is made at the rate in force on the day of payment, unless a warning indicating a previous rate has already been sent. However, in the case of restoration, payment of fees due which have not been paid by the date of entry of the decision in the National Patent Register must be made at the rate in force on that date.