ZIP Codes in North Sioux City, SD
North Sioux City uses 1 ZIP code, all in Union County. Pick one below for details, or look up the full nine-digit ZIP+4 for a specific street address.
All 1 North Sioux City ZIP codes
| ZIP | Type | County | Population |
|---|---|---|---|
| 57049 | standard | Union | 7,962 |
Finding a ZIP+4 in North Sioux City
Knowing which of these 1 ZIP codes covers an address only gets you partway. The four-digit extension identifies the specific delivery point — typically one side of one block. Two houses facing each other on the same North Sioux City street almost always have different ZIP+4 codes even though they share all five leading digits.
Appending ZIP+4 to a mailing list?
Upload a CSV of North Sioux City addresses and download it complete.