Postal code (also known as postal area code, which is called postal area code in Taiwan, English: postal code) is a coding method that a country or region divides the whole country in order to achieve mail sorting automation and postal network digitization and speed up mail delivery.
The postal area numbering system has become one of the standards to measure a country's communication technology and postal service level. The zip code was first invented by Ukraine and opened in December 1932, but was abandoned in the third year. Later, Germany adopted it again. Most countries or regions use zip codes in their postal systems, with a few exceptions. Ireland, Panama, Jamaica and Hong Kong do not use zip codes, while New Zealand only uses them when posting large amounts of mail.
In fact, you don't need a postal code to send letters or other things in Hong Kong, China, because Hong Kong Post has an independent nine letter postal code, but it hasn't been made public. In addition, Hong Kong is a small city, so it is very convenient to send letters, so there is no need for a zip code. However, if you send letters or parcels abroad, you need to abide by the relevant foreign regulations and enter the corresponding English address and zip code.