How to determine the date of patent application: the postmark date of qualified patent application documents sent by post office is the date of application; Submit the patent application documents directly to the China National Intellectual Property Administration Patent Office, and the date when the accepting department receives the patent application documents shall be the filing date. An applicant who files an application for a patent for invention or utility model with the administrative department for patent in the State Council within 12 months from the date when he first filed an application in China may enjoy priority.
legal ground
According to article 28 of the patent law of People's Republic of China (PRC), which came into effect on June 1 20265438.
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.