The ID card starting with 420 is from Hubei Province. Shanghai's ID number starts with "3 10", "3 10 1" stands for Shanghai's urban area and "3 102" stands for Shanghai's jurisdiction.

The coding rules of ID number are clearly stipulated in GB11643-1999 "Citizen Identity Number":

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. According to the first three address codes, you can judge which province the ID card belongs to.