ZIP Code 54234 — Sister Bay, WI
54234 is a standard (street delivery) ZIP code serving Sister Bay, Wisconsin, in Door 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 54234 at a glance
| ZIP code | 54234 |
|---|---|
| Primary city | Sister Bay |
| State | Wisconsin (WI) |
| County | Door FIPS 55029 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 2,158 |
| Coordinates | 45.183770, -87.092390 |
How ZIP+4 works in 54234
The four digits after the hyphen encode a delivery segment inside 54234. 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 54234 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 54234.
| ZIP | City | Distance |
|---|---|---|
| 54211 | Ephraim, WI | 4 mi |
| 54210 | Ellison Bay, WI | 5.6 mi |
| 54202 | Baileys Harbor, WI | 7.6 mi |
| 54212 | Fish Creek, WI | 8 mi |
| 54209 | Egg Harbor, WI | 14.8 mi |
| 54246 | Washington Island, WI | 16.3 mi |
| 49858 | Menominee, MI | 24 mi |
| 49893 | Wallace, MI | 25.9 mi |
| 54235 | Sturgeon Bay, WI | 27.3 mi |
| 49887 | Stephenson, MI | 28.7 mi |
| 49848 | Ingalls, MI | 29.7 mi |
| 49812 | Carney, MI | 34.5 mi |
Questions about 54234
What is the ZIP+4 code for 54234?
54234 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 54234, you need to look up a specific street address to get them.
What city is 54234?
54234 is assigned to Sister Bay, Wisconsin, in Door 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.