legal ground
Article 42 of the Patent Law of People's Republic of China (PRC)
The term of the invention patent right is 20 years, and the term of the utility model patent right and the design patent right is 10 years, both counting from the date of application.
Article 43
The patentee shall pay the annual fee from the year when the patent right is granted.
Article 44
In any of the following circumstances, the patent right shall be terminated before the expiration of the time limit:
(a) failing to pay the annual fee in accordance with the provisions;
(2) The patentee waives his patent right in writing. Where the patent right is terminated before the expiration of the time limit, it shall be registered and announced by the patent administration department of the State Council.
Article 98 of the Detailed Rules for the Implementation of the Patent Law of People's Republic of China (PRC)
The annual fee after the year in which 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.