The application fee cannot be reduced.
According to Article 5 of the "Measures for Mitigating Patent Fees", a patent applicant may request to defer the payment of the five types of fees specified in Article 3 of these Measures when filing a patent application. After the Patent Office accepts a patent application, the application fee will no longer be slowed down. The applicant or patentee can only request for deferment of payment of fees that have not yet expired, and the request for deferment of fees should be submitted two and a half months before the expiration of the relevant fee payment period.
Therefore, the request for reduction must be submitted together with the patent application materials, otherwise the application fee will not be reduced.