ZIP Code 51442 — Denison, IA
51442 is a standard (street delivery) ZIP code serving Denison, Iowa, in Crawford 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 51442 at a glance
| ZIP code | 51442 |
|---|---|
| Primary city | Denison |
| State | Iowa (IA) |
| County | Crawford FIPS 19047 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 9,692 |
| Coordinates | 42.026960, -95.359150 |
How ZIP+4 works in 51442
The four digits after the hyphen encode a delivery segment inside 51442. 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 51442 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 51442.
| ZIP | City | Distance |
|---|---|---|
| 51520 | Arion, IA | 6.5 mi |
| 51441 | Deloit, IA | 6.7 mi |
| 51465 | Vail, IA | 9.3 mi |
| 51528 | Dow City, IA | 10 mi |
| 51461 | Schleswig, IA | 11.7 mi |
| 51439 | Charter Oak, IA | 12.1 mi |
| 51448 | Kiron, IA | 12.4 mi |
| 51454 | Manilla, IA | 12.8 mi |
| 51460 | Ricketts, IA | 13.1 mi |
| 51467 | Westside, IA | 13.2 mi |
| 51527 | Defiance, IA | 13.7 mi |
| 51432 | Aspinwall, IA | 13.9 mi |
Questions about 51442
What is the ZIP+4 code for 51442?
51442 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 51442, you need to look up a specific street address to get them.
What city is 51442?
51442 is assigned to Denison, Iowa, in Crawford 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.