ZIP Code 51301 — Spencer, IA
51301 is a standard (street delivery) ZIP code serving Spencer, Iowa, in Clay 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 51301 at a glance
| ZIP code | 51301 |
|---|---|
| Primary city | Spencer |
| State | Iowa (IA) |
| County | Clay FIPS 19041 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 12,638 |
| Coordinates | 43.153140, -95.149730 |
How ZIP+4 works in 51301
The four digits after the hyphen encode a delivery segment inside 51301. 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 51301 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 51301.
| ZIP | City | Distance |
|---|---|---|
| 51340 | Fostoria, IA | 6 mi |
| 51333 | Dickens, IA | 7.5 mi |
| 51357 | Royal, IA | 9.4 mi |
| 51343 | Greenville, IA | 9.5 mi |
| 51338 | Everly, IA | 9.5 mi |
| 51341 | Gillett Grove, IA | 10.9 mi |
| 51351 | Milford, IA | 11.4 mi |
| 51358 | Ruthven, IA | 12.9 mi |
| 51364 | Terril, IA | 13.8 mi |
| 51331 | Arnolds Park, IA | 14.6 mi |
| 51366 | Webb, IA | 15.1 mi |
| 51346 | Hartley, IA | 15.7 mi |
Questions about 51301
What is the ZIP+4 code for 51301?
51301 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 51301, you need to look up a specific street address to get them.
What city is 51301?
51301 is assigned to Spencer, Iowa, in Clay 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.