ZIP Code 51023 — Hawarden, IA
51023 is a standard (street delivery) ZIP code serving Hawarden, Iowa, in Sioux 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 51023 at a glance
| ZIP code | 51023 |
|---|---|
| Primary city | Hawarden |
| State | Iowa (IA) |
| County | Sioux FIPS 19167 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 3,473 |
| Coordinates | 43.008930, -96.468450 |
How ZIP+4 works in 51023
The four digits after the hyphen encode a delivery segment inside 51023. 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 51023 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 51023.
| ZIP | City | Distance |
|---|---|---|
| 51011 | Chatsworth, IA | 6.8 mi |
| 51027 | Ireton, IA | 7.7 mi |
| 57034 | Hudson, SD | 8.9 mi |
| 57001 | Alcester, SD | 9.4 mi |
| 51001 | Akron, IA | 12.4 mi |
| 57027 | Fairview, SD | 13 mi |
| 51250 | Sioux Center, IA | 13.9 mi |
| 51036 | Maurice, IA | 14.3 mi |
| 51247 | Rock Valley, IA | 14.3 mi |
| 57004 | Beresford, SD | 17 mi |
| 51008 | Brunsville, IA | 17 mi |
| 51041 | Orange City, IA | 19.8 mi |
Questions about 51023
What is the ZIP+4 code for 51023?
51023 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 51023, you need to look up a specific street address to get them.
What city is 51023?
51023 is assigned to Hawarden, Iowa, in Sioux 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.