Among the six digits of postal code, the first two digits indicate the province (municipality directly under the central government, autonomous region); The third digit indicates the postal area; The fourth digit indicates the county (city); The last two digits indicate the office. Among the six digits of postal code, the first two digits indicate the province (municipality directly under the central government, autonomous region); The third digit indicates the postal area; The fourth digit indicates the county (city); The last two digits indicate the office.