The postcode of 5 16400 is: 1, the second place is 5 1: Guangdong province, the third place is 6: Shanwei postal area, the fourth place is 4: Haifeng county post office, and the last two places are 00: all delivery areas in Haifeng county.

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.