ZIP Code 51235 — Doon, IA
51235 is a standard (street delivery) ZIP code serving Doon, Iowa, in Lyon 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 51235 at a glance
| ZIP code | 51235 |
|---|---|
| Primary city | Doon |
| State | Iowa (IA) |
| County | Lyon FIPS 19119 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 1,007 |
| Coordinates | 43.294880, -96.215310 |
How ZIP+4 works in 51235
The four digits after the hyphen encode a delivery segment inside 51235. 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 51235 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 51235.
| ZIP | City | Distance |
|---|---|---|
| 51230 | Alvord, IA | 6.8 mi |
| 51239 | Hull, IA | 7.3 mi |
| 51247 | Rock Valley, IA | 9.3 mi |
| 51246 | Rock Rapids, IA | 9.5 mi |
| 51237 | George, IA | 11.2 mi |
| 51242 | Lester, IA | 11.3 mi |
| 51234 | Boyden, IA | 12 mi |
| 51240 | Inwood, IA | 12.2 mi |
| 51250 | Sioux Center, IA | 14.5 mi |
| 51244 | Matlock, IA | 14.5 mi |
| 56173 | Steen, MN | 15.9 mi |
| 57027 | Fairview, SD | 16.3 mi |
Questions about 51235
What is the ZIP+4 code for 51235?
51235 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 51235, you need to look up a specific street address to get them.
What city is 51235?
51235 is assigned to Doon, Iowa, in Lyon 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.