ZIP Code 51249 — Sibley, IA
51249 is a standard (street delivery) ZIP code serving Sibley, Iowa, in Osceola 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 51249 at a glance
| ZIP code | 51249 |
|---|---|
| Primary city | Sibley |
| State | Iowa (IA) |
| County | Osceola FIPS 19143 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 3,564 |
| Coordinates | 43.410680, -95.732030 |
How ZIP+4 works in 51249
The four digits after the hyphen encode a delivery segment inside 51249. 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 51249 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 51249.
| ZIP | City | Distance |
|---|---|---|
| 56117 | Bigelow, MN | 8.3 mi |
| 51232 | Ashton, IA | 8.7 mi |
| 51243 | Little Rock, IA | 8.8 mi |
| 51354 | Ocheyedan, IA | 9.5 mi |
| 51350 | Melvin, IA | 9.8 mi |
| 51237 | George, IA | 14.3 mi |
| 56168 | Rushmore, MN | 14.6 mi |
| 51248 | Sanborn, IA | 14.7 mi |
| 51345 | Harris, IA | 15 mi |
| 51244 | Matlock, IA | 15.3 mi |
| 56187 | Worthington, MN | 16.4 mi |
| 51201 | Sheldon, IA | 17.1 mi |
Questions about 51249
What is the ZIP+4 code for 51249?
51249 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 51249, you need to look up a specific street address to get them.
What city is 51249?
51249 is assigned to Sibley, Iowa, in Osceola 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.