Indicates the administrative division code of the county (city, town, district) where the permanent residence of the coding object is located. 1-2 codes of provinces, autonomous regions and municipalities directly under the central government; 3-4 digits of code of prefecture-level cities, leagues and autonomous prefectures; 5-6 county, county-level city and district codes.

2. Serial number (digits 15 to 17 of ID number)

The serial number assigned to the person born in the same year, month and day in the area identified by the address code.

Among them, the seventeenth odd number is for men and the even number is for women.

3. Check code (last digit of ID number)

It is a check code calculated according to the previous 17 bit code and the check code of ISO 7064: 1983. MOD 1 1-2。

As the tail number, the check code is calculated by the numbering unit according to a unified formula.

Date of birth code:

(7th to14th digits of the ID number) indicates the year, month and day when the coded object was born, where the year is represented by four digits, and there is no separator between the year, month and day.

For example:1981May 1 1 daily1981051.

According to GB/T7408.