ZIP Code 54205 — Casco, WI
54205 is a standard (street delivery) ZIP code serving Casco, Wisconsin, in Kewaunee 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 54205 at a glance
| ZIP code | 54205 |
|---|---|
| Primary city | Casco |
| State | Wisconsin (WI) |
| County | Kewaunee FIPS 55061 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 2,229 |
| Coordinates | 44.604440, -87.629120 |
How ZIP+4 works in 54205
The four digits after the hyphen encode a delivery segment inside 54205. 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 54205 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 54205.
| ZIP | City | Distance |
|---|---|---|
| 54217 | Luxemburg, WI | 5.9 mi |
| 54201 | Algoma, WI | 6.7 mi |
| 54213 | Forestville, WI | 8.4 mi |
| 54229 | New Franken, WI | 9.8 mi |
| 54204 | Brussels, WI | 10.9 mi |
| 54216 | Kewaunee, WI | 11.8 mi |
| 54311 | Green Bay, WI | 15.5 mi |
| 54302 | Green Bay, WI | 18.4 mi |
| 54208 | Denmark, WI | 18.6 mi |
| 54173 | Suamico, WI | 20 mi |
| 54141 | Little Suamico, WI | 20.4 mi |
| 54235 | Sturgeon Bay, WI | 20.6 mi |
Questions about 54205
What is the ZIP+4 code for 54205?
54205 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 54205, you need to look up a specific street address to get them.
What city is 54205?
54205 is assigned to Casco, Wisconsin, in Kewaunee 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.