居民身份证号码是按照国家的标准编制的,由18位组成:前六位为行政区划代码,第七至第十四位为出生日期码,第15至17位为顺序码,第18位为校验码。作为尾号的校验码,是由号码编制单位按统一的公式计算出来的,如果某人的尾号是0-9,都不会出现X,但如果尾号是10,那么就得用X来代替,因为如果用10做尾号,那么此人的身份证就变成了19位, The ID number is compiled according to the national standards and consists of 18 persons: the first six digits are the administrative divisions code, the seventh to fourteenth digits are the date of birth code, the first 15th to the 17th digits are the ordinal digits, and the 18th is the Check code. The check code as the tail number is calculated by the numbering unit according to a unified formula. If someone’s tail number is 0-9, X does not appear, but if the tail number is 10, then X Instead, because if you do the tail number with 10, then the person’s ID becomes 19,