ZIP Code 54423 — Custer, WI
54423 is a standard (street delivery) ZIP code serving Custer, Wisconsin, in Portage 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 54423 at a glance
| ZIP code | 54423 |
|---|---|
| Primary city | Custer |
| State | Wisconsin (WI) |
| County | Portage FIPS 55097 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 2,394 |
| Coordinates | 44.580490, -89.416420 |
How ZIP+4 works in 54423
The four digits after the hyphen encode a delivery segment inside 54423. 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 54423 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 54423.
| ZIP | City | Distance |
|---|---|---|
| 54482 | Stevens Point, WI | 5 mi |
| 54473 | Rosholt, WI | 5.6 mi |
| 54407 | Amherst Junction, WI | 7 mi |
| 54458 | Nelsonville, WI | 7.7 mi |
| 54481 | Stevens Point, WI | 11.6 mi |
| 54406 | Amherst, WI | 12.8 mi |
| 54467 | Plover, WI | 12.9 mi |
| 54945 | Iola, WI | 13.7 mi |
| 54977 | Scandinavia, WI | 15 mi |
| 54440 | Hatley, WI | 15.6 mi |
| 54443 | Junction City, WI | 16.7 mi |
| 54455 | Mosinee, WI | 18.2 mi |
Questions about 54423
What is the ZIP+4 code for 54423?
54423 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 54423, you need to look up a specific street address to get them.
What city is 54423?
54423 is assigned to Custer, Wisconsin, in Portage 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.