Legal basis: Article 98 of the Detailed Rules for the Implementation of the Patent Law of People's Republic of China (PRC) stipulates that the annual fee after the year when the patent right is granted shall be paid before the expiration of the previous year. If the patentee fails to pay or fails to pay in full, the patent administration department of the State Council shall notify the patentee to pay the annual fee within 6 months from the date of expiration, and pay the late fee at the same time; The amount of the late payment fee is calculated by adding 5% of the full annual fee of the current year for every 1 month that exceeds the prescribed payment time; If it is not paid at the expiration of the time limit, the patent right shall be terminated from the date when the annual fee should be paid.