What is the application number of the national intellectual property patent?

The national intellectual property patent application number is a serial number provided by China National Intellectual Property Administration when applying to the applicant. It is the basis for the applicant to issue various notices (including acceptance notice, correction notice, opinion review, authorization notice and payment notice) during the application process, and the applicant also responds and pays fees according to the application number. The application number mainly consists of 13 digits, the first 4 digits are the year, the last 8 digits are the serial number, and the last digit is the inspection number.