ZIP Code 40171 — Union Star, KY
40171 is a standard (street delivery) ZIP code serving Union Star, Kentucky, in Breckinridge 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 40171 at a glance
| ZIP code | 40171 |
|---|---|
| Primary city | Union Star |
| State | Kentucky (KY) |
| County | Breckinridge FIPS 21027 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 272 |
| Coordinates | 37.964350, -86.435770 |
How ZIP+4 works in 40171
The four digits after the hyphen encode a delivery segment inside 40171. 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 40171 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 40171.
| ZIP | City | Distance |
|---|---|---|
| 40170 | Stephensport, KY | 3.3 mi |
| 40161 | Rhodelia, KY | 3.4 mi |
| 40157 | Payneville, KY | 5.1 mi |
| 40176 | Webster, KY | 5.6 mi |
| 47574 | Rome, IN | 7 mi |
| 47525 | Derby, IN | 7.8 mi |
| 47520 | Cannelton, IN | 8.6 mi |
| 40104 | Battletown, KY | 10.1 mi |
| 40146 | Irvington, KY | 10.3 mi |
| 47551 | Leopold, IN | 12.9 mi |
| 40143 | Hardinsburg, KY | 12.9 mi |
| 40142 | Guston, KY | 13.3 mi |
Questions about 40171
What is the ZIP+4 code for 40171?
40171 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 40171, you need to look up a specific street address to get them.
What city is 40171?
40171 is assigned to Union Star, Kentucky, in Breckinridge 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.