The difference between Chongqing ID card 5 1 and 50.

The difference between ID cards 5 1 and 50 is as follows:

Before Chongqing became a municipality directly under the Central Government, the prefix of the ID card used was 5 1, the same as that used in Sichuan. 1997 After Chongqing became a municipality directly under the Central Government, the prefix of Chongqing's ID card became 50.

The first place of the ID number is the area number, and the southwest is 5, while Sichuan Province has already used the number 5 1. According to the principle that municipalities directly under the Central Government rank ahead of provinces and autonomous regions, the first two digits of Chongqing's ID number are 50, so it is the only place in China where the second digit of the ID number is 0.