Legal analysis: According to the law, the date when the patent administrative department of the State Council receives the patent application documents is the filing date. If the application documents are mailed, the postmark date of mailing shall be the application date. The patentee shall pay the annual fee from the year when the patent right is granted. After receiving an application for a patent for invention, the administrative department for patent in the State Council, after preliminary examination, finds that it conforms to the provisions of this Law, and shall publish it immediately after 18 months from the date of application. The patent administration department of the State Council may publish its application at an early date upon the request of the applicant.
Legal basis: Article 28 of the Patent Law of People's Republic of China (PRC), the date when the patent administrative department of the State Council receives the patent application documents is the filing date. If the application documents are mailed, the postmark date of mailing shall be the application date.