ZIP Code 40107 — Boston, KY
40107 is a standard (street delivery) ZIP code serving Boston, Kentucky, in Nelson 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 40107 at a glance
| ZIP code | 40107 |
|---|---|
| Primary city | Boston |
| State | Kentucky (KY) |
| County | Nelson FIPS 21179 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 2,187 |
| Coordinates | 37.769520, -85.637980 |
How ZIP+4 works in 40107
The four digits after the hyphen encode a delivery segment inside 40107. 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 40107 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 40107.
| ZIP | City | Distance |
|---|---|---|
| 40150 | Lebanon Junction, KY | 7.7 mi |
| 40051 | New Haven, KY | 8.7 mi |
| 40004 | Bardstown, KY | 9.5 mi |
| 40110 | Clermont, KY | 11.4 mi |
| 42701 | Elizabethtown, KY | 11.8 mi |
| 40013 | Coxs Creek, KY | 14 mi |
| 42748 | Hodgenville, KY | 14.3 mi |
| 40052 | New Hope, KY | 14.5 mi |
| 40037 | Loretto, KY | 14.7 mi |
| 40049 | Nerinx, KY | 15 mi |
| 40165 | Shepherdsville, KY | 15.7 mi |
| 40062 | Saint Francis, KY | 16.2 mi |
Questions about 40107
What is the ZIP+4 code for 40107?
40107 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 40107, you need to look up a specific street address to get them.
What city is 40107?
40107 is assigned to Boston, Kentucky, in Nelson 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.