If you entrust an agent, the agency fee is generally around 5000.
Legal basis: People's Republic of China (PRC) Patent Law.
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 45 From the date when the patent administration department in the State Council announced the grant of the patent right, if any unit or individual thinks that the grant of the patent right is not in conformity with the relevant provisions of this Law, it may request the patent administration department in the State Council to declare the patent right invalid.