3.5 years ago, pay the annual maintenance fee of 5-8 years (980 dollars for large enterprises and 490 dollars for small enterprises);
7.5 years ago, pay the maintenance fee of 9- 12 years ($2,480 for large enterprises and $0/240 for small enterprises);
1 1.5 years ago, pay the annual maintenance fee for the remaining patent term ($465,438 for large enterprises+$+0 10/0 for small enterprises, $2,055 for small enterprises).
For information about foreign-related patent applications, please refer to the content of Han Zhi Guanghua website, which is more detailed.