ZIP Code 54121 — Florence, WI
54121 is a standard (street delivery) ZIP code serving Florence, Wisconsin, in Florence 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 54121 at a glance
| ZIP code | 54121 |
|---|---|
| Primary city | Florence |
| State | Wisconsin (WI) |
| County | Florence FIPS 55037 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 3,257 |
| Coordinates | 45.863850, -88.328990 |
How ZIP+4 works in 54121
The four digits after the hyphen encode a delivery segment inside 54121. 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 54121 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 54121.
| ZIP | City | Distance |
|---|---|---|
| 54120 | Fence, WI | 10.6 mi |
| 49802 | Kingsford, MI | 12.9 mi |
| 49902 | Alpha, MI | 13 mi |
| 49801 | Iron Mountain, MI | 15.4 mi |
| 54103 | Armstrong Creek, WI | 16.9 mi |
| 49927 | Gaastra, MI | 17.1 mi |
| 49876 | Quinnesec, MI | 17.4 mi |
| 54119 | Dunbar, WI | 17.9 mi |
| 54151 | Niagara, WI | 18.6 mi |
| 54125 | Goodman, WI | 19.1 mi |
| 49920 | Crystal Falls, MI | 19.2 mi |
| 54542 | Long Lake, WI | 19.5 mi |
Questions about 54121
What is the ZIP+4 code for 54121?
54121 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 54121, you need to look up a specific street address to get them.
What city is 54121?
54121 is assigned to Florence, Wisconsin, in Florence 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.