ZIP Code 51246 — Rock Rapids, IA
51246 is a standard (street delivery) ZIP code serving Rock Rapids, 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 51246 at a glance
| ZIP code | 51246 |
|---|---|
| Primary city | Rock Rapids |
| State | Iowa (IA) |
| County | Lyon FIPS 19119 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 4,041 |
| Coordinates | 43.427640, -96.165640 |
How ZIP+4 works in 51246
The four digits after the hyphen encode a delivery segment inside 51246. 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 51246 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 51246.
| ZIP | City | Distance |
|---|---|---|
| 56173 | Steen, MN | 7.7 mi |
| 51242 | Lester, IA | 8.6 mi |
| 56129 | Ellsworth, MN | 9.2 mi |
| 51230 | Alvord, IA | 9.3 mi |
| 51235 | Doon, IA | 9.5 mi |
| 51237 | George, IA | 10.3 mi |
| 56146 | Kanaranzi, MN | 11 mi |
| 56138 | Hills, MN | 13.1 mi |
| 51243 | Little Rock, IA | 13.2 mi |
| 51241 | Larchwood, IA | 14.8 mi |
| 56158 | Magnolia, MN | 14.9 mi |
| 51239 | Hull, IA | 15.6 mi |
Questions about 51246
What is the ZIP+4 code for 51246?
51246 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 51246, you need to look up a specific street address to get them.
What city is 51246?
51246 is assigned to Rock Rapids, 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.