The applicant for a patent for invention may amend the application for a patent for invention within three months from the date of filing a request for substantive examination and receiving the notice from the Patent Office that the application for a patent for invention has entered the substantive examination stage.
According to the Patent Law, the examination and approval procedure of an application for a patent for invention includes five stages: acceptance, preliminary examination, publication, actual examination and authorization. The application for a patent for utility model or design does not undergo early publication and substantive examination in the examination and approval, and there are only three stages: acceptance, preliminary examination and authorization.