ZIP Code 53548 — Janesville, WI
53548 is a standard (street delivery) ZIP code serving Janesville, Wisconsin, in Rock 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 53548 at a glance
| ZIP code | 53548 |
|---|---|
| Primary city | Janesville |
| State | Wisconsin (WI) |
| County | Rock FIPS 55105 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 19,916 |
| Coordinates | 42.689070, -89.130950 |
How ZIP+4 works in 53548
The four digits after the hyphen encode a delivery segment inside 53548. 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 53548 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 Janesville
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 53548.
| ZIP | City | Distance |
|---|---|---|
| 53537 | Footville, WI | 4.2 mi |
| 53545 | Janesville, WI | 5.6 mi |
| 53501 | Afton, WI | 6.5 mi |
| 53576 | Orfordville, WI | 7 mi |
| 53536 | Evansville, WI | 8.7 mi |
| 53546 | Janesville, WI | 9.6 mi |
| 53511 | Beloit, WI | 10 mi |
| 53534 | Edgerton, WI | 11.1 mi |
| 53563 | Milton, WI | 12 mi |
| 53520 | Brodhead, WI | 13.2 mi |
| 53505 | Avalon, WI | 16 mi |
| 53502 | Albany, WI | 16 mi |
Questions about 53548
What is the ZIP+4 code for 53548?
53548 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 53548, you need to look up a specific street address to get them.
What city is 53548?
53548 is assigned to Janesville, Wisconsin, in Rock 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.