ZIP Code 51031 — Le Mars, IA
51031 is a standard (street delivery) ZIP code serving Le Mars, Iowa, in Plymouth 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 51031 at a glance
| ZIP code | 51031 |
|---|---|
| Primary city | Le Mars |
| State | Iowa (IA) |
| County | Plymouth FIPS 19149 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 12,808 |
| Coordinates | 42.802820, -96.180920 |
How ZIP+4 works in 51031
The four digits after the hyphen encode a delivery segment inside 51031. 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 51031 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 51031.
| ZIP | City | Distance |
|---|---|---|
| 51008 | Brunsville, IA | 4.4 mi |
| 51045 | Oyens, IA | 6.4 mi |
| 51038 | Merrill, IA | 9.6 mi |
| 51036 | Maurice, IA | 11.6 mi |
| 51050 | Remsen, IA | 11.8 mi |
| 51024 | Hinton, IA | 13.3 mi |
| 51027 | Ireton, IA | 13.5 mi |
| 51003 | Alton, IA | 15.9 mi |
| 51041 | Orange City, IA | 16.2 mi |
| 51028 | Kingsley, IA | 17 mi |
| 51108 | Sioux City, IA | 18.4 mi |
| 51001 | Akron, IA | 18.6 mi |
Questions about 51031
What is the ZIP+4 code for 51031?
51031 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 51031, you need to look up a specific street address to get them.
What city is 51031?
51031 is assigned to Le Mars, Iowa, in Plymouth 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.