According to the postal code database, the postal code of Hai 'an City, Nantong City, Jiangsu Province is 226600, with the first two digits 22 representing Jiangsu Province, the last six representing Nantong City, the fourth being Hai 'an City in the sixth generation, and the last two digits 00 representing the specific delivery area.

Hai 'an is a county-level city under the jurisdiction of Jiangsu Province, which is managed by Nantong City. It is located in the south-central part of Jiangsu Province, in the Suzhong Plain, bordering the Yellow Sea in the east.