ZIP Code 51401 — Carroll, IA
51401 is a standard (street delivery) ZIP code serving Carroll, Iowa, in Carroll 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 51401 at a glance
| ZIP code | 51401 |
|---|---|
| Primary city | Carroll |
| State | Iowa (IA) |
| County | Carroll FIPS 19027 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 11,990 |
| Coordinates | 42.065160, -94.870680 |
How ZIP+4 works in 51401
The four digits after the hyphen encode a delivery segment inside 51401. 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 51401 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 51401.
| ZIP | City | Distance |
|---|---|---|
| 51452 | Lidderdale, IA | 6 mi |
| 51444 | Halbur, IA | 6.4 mi |
| 51430 | Arcadia, IA | 8.1 mi |
| 51443 | Glidden, IA | 8.5 mi |
| 51436 | Breda, IA | 10.9 mi |
| 51440 | Dedham, IA | 11 mi |
| 51463 | Templeton, IA | 11.1 mi |
| 51459 | Ralston, IA | 12 mi |
| 51451 | Lanesboro, IA | 12.2 mi |
| 51467 | Westside, IA | 12.2 mi |
| 51455 | Manning, IA | 14.4 mi |
| 51433 | Auburn, IA | 14.6 mi |
Questions about 51401
What is the ZIP+4 code for 51401?
51401 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 51401, you need to look up a specific street address to get them.
What city is 51401?
51401 is assigned to Carroll, Iowa, in Carroll 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.