legal ground
Article 10 of the Measures for the Reduction and Exemption of Patent Fees
For the request for fee reduction approved by China National Intellectual Property Administration, the patent applicant or patentee shall pay the patent fee according to the approved amount within the prescribed time limit. If the patent applicant or patentee changes after the request for fee reduction is approved, the changed patent applicant or patentee shall resubmit the request for fee reduction for unpaid fees.