What is the basis of domestic patent priority and what are the conditions for applying for domestic patent priority?

According to the relevant provisions of the Patent Law and the detailed rules for the implementation of the Patent Law, if an applicant applies for a patent for invention or utility model for the first time in a foreign country within 12 months, or applies for a patent for design for the first time in a foreign country within 6 months, and applies for a patent on the same subject in China, he can enjoy the priority according to the agreement signed between the foreign country and China or the international treaties to which he is a party, or according to the principle of mutual recognition of priority; 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.

The applicant claims domestic priority, and if the earlier application is an application for a patent for invention, he may file an application for a patent for invention or utility model on the same subject; Where the earlier application is an application for a patent for utility model, an application for a patent for utility model or invention may be filed on the same subject. However, when the latter application is filed, if the subject matter of the former application is under any of the following circumstances, it shall not be used as the basis for claiming domestic priority:

(1) claiming foreign priority or domestic priority;

(2) The patent right has been granted;

(3) It is a divisional application filed in accordance with regulations.

Where the applicant claims domestic priority, the earlier application shall be deemed to have been withdrawn from the date of filing the later application.

The applicant may claim one or more priorities in a patent application; Where multiple priorities are claimed, the priority period of the application shall be calculated from the earliest priority date.