According to the postal code database, the postal code of Nanxian County in Yiyang City is 4 13200, with the first two digits 4 1 representing Hunan Province, the third digit 3 representing Yiyang City and the fourth digit 2 representing Nanxian County. The last two digits 00 represent a specific delivery area.

Yiyang Nanxian County is located in the abdomen of Dongting Lake Plain, with a total area of 1075 square kilometers, and is known as the land of plenty.