5 18 103。 In the postcode database of Baoan District, Shenzhen, Guangdong Province, the postcode of Fuhai Street in Baoan, Shenzhen is 5 18 103. Postal code is a coding method that a country or region divides the whole country in order to realize the automation of mail sorting and the digitalization of postal network and speed up the delivery of mail. Postal coding system has become one of the standards to measure a country's communication technology and postal service level.