45 years ago today, on July 1, 1980 (May 19, 1980 lunar calendar), China began to promote the postal code system. Postal code is a special code for postal communication to realize mail machine sorting. It is a necessary tool to realize postal modernization. The ultimate goal is to improve the speed and accuracy of your letters in the delivery process. Therefore, it is necessary to indicate the postal code when delivering letters and packages. If you do not know the postal code of the other party (recipient), you can consult on the postal code query device set up in the business room of the local post office or the multimedia microcomputer query system for postal business, or you can inquire through the 11185 special service phone. In order to realize the automation of mail sorting and the digitization of postal networks, and speed up the delivery of mail, more than 40 countries in the world have successively implemented the postal code system, which is used as one of the standards to measure the level of communication technology and postal service in a country. The postal code rules of various countries are not uniform. Postal code is a measure taken by the post and telecommunications department to realize postal modernization, originating in the United Kingdom. In the early 1950s, the United Kingdom began to study postal codes, and in 1959 it was piloted in the Norwich postal area, which attracted the attention of many countries. West Germany officially announced the four-digit postal code in 1961, becoming the first country in the world to implement postal codes nationwide. Subsequently, the United States, Britain, France, Australia, Switzerland and other countries have successively implemented them nationwide. After 1965, with the wide application of machinery and equipment, the superiority of zip codes became more obvious, and countries such as Japan, Italy, Canada, the Netherlands and Sweden also implemented zip codes one after another. By the beginning of 1988, more than 50 countries and regions in the world had implemented the zip code system. The zip code is composed of Arabic numerals, representing a special code for the post office that delivers mail, and it is also the code for the communication of residents and units within the delivery range of this office. Our country began to develop our country's zip code in 1974. After about 5 years, the "National Postal Code Pilot Plan" was formulated, which was piloted in Liaoning, Shanghai, Jiangsu and other provinces and cities in 1978. It was officially promoted nationwide on July 1, 1980. Later, due to various reasons, the implementation work was completely stopped. It was not until 1986 that the National Postal Work Conference decided to re-implement postal codes across the country. The postal code currently used in our country is the "four-level six-code" system. That is, each group of codes consists of six Arabic digits, which represent the province (autonomous region, municipality directly under the Central Government), postal district, county (city) post and telecommunications office (district) four levels. The first two digits of the six digits represent the province (autonomous region, municipality directly under the Central Government), the first three represent the postal district, the first four represent the county (city) post and telecommunications office, and the last two are the number of the delivery office (district).