ZIP Code 50255 — Thornburg, IA
50255 is a standard (street delivery) ZIP code serving Thornburg, Iowa, in Keokuk 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 50255 at a glance
| ZIP code | 50255 |
|---|---|
| Primary city | Thornburg |
| State | Iowa (IA) |
| County | Keokuk FIPS 19107 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 51 |
| Coordinates | 41.455930, -92.332070 |
How ZIP+4 works in 50255
The four digits after the hyphen encode a delivery segment inside 50255. 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 50255 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 50255.
| ZIP | City | Distance |
|---|---|---|
| 50136 | Keswick, IA | 2.4 mi |
| 50268 | What Cheer, IA | 3.7 mi |
| 50104 | Gibson, IA | 3.9 mi |
| 50027 | Barnes City, IA | 7.3 mi |
| 52355 | Webster, IA | 7.7 mi |
| 52222 | Deep River, IA | 8.3 mi |
| 52550 | Delta, IA | 9.8 mi |
| 52586 | Rose Hill, IA | 10.3 mi |
| 52591 | Sigourney, IA | 11.8 mi |
| 52308 | Millersburg, IA | 12.1 mi |
| 52221 | Guernsey, IA | 12.8 mi |
| 50171 | Montezuma, IA | 13.4 mi |
Questions about 50255
What is the ZIP+4 code for 50255?
50255 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 50255, you need to look up a specific street address to get them.
What city is 50255?
50255 is assigned to Thornburg, Iowa, in Keokuk 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.