Postal code is a special code composed of Arabic numerals, which represents the post office that delivers mail. It is a special code for postal communication to realize mail sorting, and it is also a necessary tool to realize postal modernization. The ultimate goal is to improve the speed and accuracy of your letter delivery. Therefore, when handing in letters and parcels, be sure to indicate the postal code. In order to realize the automation of mail sorting and the digitalization of postal network, and speed up the delivery of mail, more than 40 countries in the world have successively implemented postal coding system, which is regarded as one of the standards to measure the communication technology and postal service level of a country.