Id number *** 18 digits: AAAAAABBBBBBCCCD.
1, number structure
Citizenship number is a characteristic combination code, which consists of 17 bit ontology code and check code. The order from left to right is: six-digit address code, eight-digit date of birth code, three-digit serial code and one-digit check code.
2. Address code (first six digits)
The administrative division code of the county (city, flag, district) where the permanent residence of the coding object is located shall be implemented according to GB/T2260.
3 date of birth code (seventh to fourteenth digits)
Indicates the year, month and day when the coded object was born, which is implemented according to GB/T7408. There is no separator between the year, month and day codes.
4. Sequence code (digits 15 to 17)
It refers to the serial number of people born in the same year, month and day in the area identified by the same address code. Odd numbers of serial numbers are assigned to men and even numbers to women.
5. Check code (bit 18)
As a suffix, the check code is calculated by the numbering unit according to a unified formula. If someone's suffix is 0-9, X will not appear, but if the suffix is 10, then X has to be used instead, because if the suffix is 10, then
This person's ID card becomes 19 digits. X is the Roman numeral 10. Replacing 10 with X can ensure that the citizen ID card meets the national standards.