ZIP Code 57231 — De Smet, SD
57231 is a standard (street delivery) ZIP code serving De Smet, South Dakota, in Kingsbury County. To mail something here you only need these five digits — but the four-digit extension narrows delivery to a single point, and it is what USPS bulk postage discounts are priced on.
ZIP code 57231 at a glance
| ZIP code | 57231 |
|---|---|
| Primary city | De Smet |
| State | South Dakota (SD) |
| County | Kingsbury FIPS 46077 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 1,724 |
| Coordinates | 44.374900, -97.582430 |
How ZIP+4 works in 57231
The four digits after the hyphen encode a delivery segment inside 57231. In practice one segment usually means:
- One side of one block — odd numbers on a street between two cross streets
- A single large building, or one floor of it
- A group of PO boxes, sometimes a single box
- A single business that receives enough mail to warrant its own code
That is why 57231 has no single ZIP+4: two neighbors across the street from each other usually have different ones. Enter a street address above and we will return the exact nine-digit code along with the standardized USPS address format.
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 57231.
| ZIP | City | Distance |
|---|---|---|
| 57249 | Lake Preston, SD | 10.7 mi |
| 57353 | Iroquois, SD | 12.4 mi |
| 57233 | Erwin, SD | 13 mi |
| 57051 | Oldham, SD | 15.8 mi |
| 57323 | Carthage, SD | 16.2 mi |
| 57221 | Bryant, SD | 17.3 mi |
| 57278 | Willow Lake, SD | 19.4 mi |
| 57214 | Badger, SD | 20.3 mi |
| 57212 | Arlington, SD | 21.7 mi |
| 57386 | Yale, SD | 22.5 mi |
| 57324 | Cavour, SD | 23.4 mi |
| 57054 | Ramona, SD | 23.7 mi |
Questions about 57231
What is the ZIP+4 code for 57231?
57231 is the five-digit ZIP code. The ZIP+4 adds four more digits that identify a specific delivery point — usually one side of a city block, a single building, or a group of PO boxes. Because those four digits change from address to address within 57231, you need to look up a specific street address to get them.
What city is 57231?
57231 is assigned to De Smet, South Dakota, in Kingsbury County.
Do I need to use the ZIP+4?
It is optional for ordinary mail, but it speeds up sorting and it is required for most USPS bulk-mail postage discounts. Many address-verification and e-commerce systems also use ZIP+4 to confirm a delivery point exists.
Need thousands of these?
Upload a CSV and get ZIP+4, county, carrier route, and delivery-point data appended to every row — or call the API directly.