The annual patent fee refers to the fee that the patentee shall pay to the Patent Office year by year from the year when the patent right is granted.
The annual fee for the year when the patent right is granted shall be paid within the time limit specified in the notice of granting the patent right issued by the Patent Office, and the annual fees for subsequent years shall be paid in advance within one month before the expiration of the previous year. If the payment is not made within one month before the expiration, the Patent Office will grant a grace period of one month. If the fee is not paid within one month after the expiration, a late fee will be incurred.