ZIP Code 66543 — Vassar, KS
66543 is a standard (street delivery) ZIP code serving Vassar, Kansas, in Osage 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 66543 at a glance
| ZIP code | 66543 |
|---|---|
| Primary city | Vassar |
| State | Kansas (KS) |
| County | Osage FIPS 20139 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 980 |
| Coordinates | 38.641750, -95.600290 |
How ZIP+4 works in 66543
The four digits after the hyphen encode a delivery segment inside 66543. 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 66543 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 66543.
| ZIP | City | Distance |
|---|---|---|
| 66451 | Lyndon, KS | 4.5 mi |
| 66528 | Quenemo, KS | 4.7 mi |
| 66076 | Pomona, KS | 8.7 mi |
| 66537 | Scranton, KS | 10 mi |
| 66510 | Melvern, KS | 10.3 mi |
| 66524 | Overbrook, KS | 11.4 mi |
| 66523 | Osage City, KS | 13 mi |
| 66414 | Carbondale, KS | 13.5 mi |
| 66095 | Williamsburg, KS | 16.3 mi |
| 66067 | Ottawa, KS | 17.6 mi |
| 66413 | Burlingame, KS | 17.8 mi |
| 66546 | Wakarusa, KS | 18.7 mi |
Questions about 66543
What is the ZIP+4 code for 66543?
66543 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 66543, you need to look up a specific street address to get them.
What city is 66543?
66543 is assigned to Vassar, Kansas, in Osage 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.