ZIP Code 42503 — Somerset, KY
42503 is a standard (street delivery) ZIP code serving Somerset, Kentucky, in Pulaski 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 42503 at a glance
| ZIP code | 42503 |
|---|---|
| Primary city | Somerset |
| State | Kentucky (KY) |
| County | Pulaski FIPS 21199 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 25,321 |
| Coordinates | 37.156770, -84.525110 |
How ZIP+4 works in 42503
The four digits after the hyphen encode a delivery segment inside 42503. 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 42503 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.
Other ZIP codes in Somerset
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 42503.
| ZIP | City | Distance |
|---|---|---|
| 42533 | Ferguson, KY | 7.2 mi |
| 42501 | Somerset, KY | 7.8 mi |
| 42567 | Eubank, KY | 8.6 mi |
| 42553 | Science Hill, KY | 9.7 mi |
| 42516 | Bethelridge, KY | 14.7 mi |
| 42519 | Burnside, KY | 15 mi |
| 40489 | Waynesburg, KY | 15.9 mi |
| 40409 | Brodhead, KY | 16.1 mi |
| 42566 | Yosemite, KY | 16.5 mi |
| 42518 | Bronston, KY | 17.2 mi |
| 40442 | Kings Mountain, KY | 17.5 mi |
| 40456 | Mount Vernon, KY | 17.6 mi |
Questions about 42503
What is the ZIP+4 code for 42503?
42503 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 42503, you need to look up a specific street address to get them.
What city is 42503?
42503 is assigned to Somerset, Kentucky, in Pulaski 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.