ZIP Code 63664 — Potosi, MO
63664 is a standard (street delivery) ZIP code serving Potosi, Missouri, in Washington 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 63664 at a glance
| ZIP code | 63664 |
|---|---|
| Primary city | Potosi |
| State | Missouri (MO) |
| County | Washington FIPS 29221 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 9,693 |
| Coordinates | 37.921610, -90.916610 |
How ZIP+4 works in 63664
The four digits after the hyphen encode a delivery segment inside 63664. 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 63664 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 63664.
| ZIP | City | Distance |
|---|---|---|
| 63622 | Belgrade, MO | 9.2 mi |
| 63660 | Mineral Point, MO | 11.7 mi |
| 63630 | Cadet, MO | 12.3 mi |
| 63648 | Irondale, MO | 13.8 mi |
| 63631 | Caledonia, MO | 13.8 mi |
| 63626 | Blackwell, MO | 15.4 mi |
| 63674 | Tiff, MO | 15.9 mi |
| 65566 | Viburnum, MO | 16.5 mi |
| 63071 | Richwoods, MO | 16.9 mi |
| 63623 | Belleview, MO | 17 mi |
| 65565 | Steelville, MO | 17.6 mi |
| 65441 | Bourbon, MO | 17.7 mi |
Questions about 63664
What is the ZIP+4 code for 63664?
63664 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 63664, you need to look up a specific street address to get them.
What city is 63664?
63664 is assigned to Potosi, Missouri, in Washington 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.