ZIP Code 53551 — Lake Mills, WI
53551 is a standard (street delivery) ZIP code serving Lake Mills, Wisconsin, in Jefferson 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 53551 at a glance
| ZIP code | 53551 |
|---|---|
| Primary city | Lake Mills |
| State | Wisconsin (WI) |
| County | Jefferson FIPS 55055 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 9,731 |
| Coordinates | 43.078310, -88.915080 |
How ZIP+4 works in 53551
The four digits after the hyphen encode a delivery segment inside 53551. 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 53551 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 53551.
| ZIP | City | Distance |
|---|---|---|
| 53038 | Johnson Creek, WI | 6.3 mi |
| 53594 | Waterloo, WI | 7.8 mi |
| 53523 | Cambridge, WI | 8.8 mi |
| 53549 | Jefferson, WI | 9.2 mi |
| 53531 | Deerfield, WI | 9.5 mi |
| 53559 | Marshall, WI | 10.3 mi |
| 53094 | Watertown, WI | 10.3 mi |
| 53538 | Fort Atkinson, WI | 11.3 mi |
| 53137 | Helenville, WI | 13.4 mi |
| 53527 | Cottage Grove, WI | 14 mi |
| 53579 | Reeseville, WI | 14.7 mi |
| 53098 | Watertown, WI | 15.5 mi |
Questions about 53551
What is the ZIP+4 code for 53551?
53551 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 53551, you need to look up a specific street address to get them.
What city is 53551?
53551 is assigned to Lake Mills, Wisconsin, in Jefferson 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.