ZIP Code 51243 — Little Rock, IA
51243 is a standard (street delivery) ZIP code serving Little Rock, 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 51243 at a glance
| ZIP code | 51243 |
|---|---|
| Primary city | Little Rock |
| State | Iowa (IA) |
| County | Lyon FIPS 19119 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 735 |
| Coordinates | 43.442500, -95.902870 |
How ZIP+4 works in 51243
The four digits after the hyphen encode a delivery segment inside 51243. 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 51243 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 51243.
| ZIP | City | Distance |
|---|---|---|
| 51237 | George, IA | 8.7 mi |
| 51249 | Sibley, IA | 8.8 mi |
| 56129 | Ellsworth, MN | 9.2 mi |
| 51232 | Ashton, IA | 10.7 mi |
| 56117 | Bigelow, MN | 12.3 mi |
| 56110 | Adrian, MN | 12.5 mi |
| 56168 | Rushmore, MN | 12.9 mi |
| 51246 | Rock Rapids, IA | 13.2 mi |
| 51244 | Matlock, IA | 13.8 mi |
| 56146 | Kanaranzi, MN | 13.8 mi |
| 56158 | Magnolia, MN | 15.8 mi |
| 51350 | Melvin, IA | 17.9 mi |
Questions about 51243
What is the ZIP+4 code for 51243?
51243 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 51243, you need to look up a specific street address to get them.
What city is 51243?
51243 is assigned to Little Rock, 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.