ZIP Code 63012 — Barnhart, MO
63012 is a standard (street delivery) ZIP code serving Barnhart, Missouri, 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 63012 at a glance
| ZIP code | 63012 |
|---|---|
| Primary city | Barnhart |
| State | Missouri (MO) |
| County | Jefferson FIPS 29099 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 10,314 |
| Coordinates | 38.335320, -90.448320 |
How ZIP+4 works in 63012
The four digits after the hyphen encode a delivery segment inside 63012. 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 63012 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 63012.
| ZIP | City | Distance |
|---|---|---|
| 63052 | Imperial, MO | 3.8 mi |
| 63070 | Pevely, MO | 3.8 mi |
| 63053 | Kimmswick, MO | 5 mi |
| 63048 | Herculaneum, MO | 6.1 mi |
| 63010 | Arnold, MO | 7.2 mi |
| 63051 | House Springs, MO | 8 mi |
| 63019 | Crystal City, MO | 8.3 mi |
| 62295 | Valmeyer, IL | 8.7 mi |
| 63050 | Hillsboro, MO | 8.7 mi |
| 63047 | Hematite, MO | 9.9 mi |
| 63049 | High Ridge, MO | 10.8 mi |
| 63129 | Saint Louis, MO | 10.8 mi |
Questions about 63012
What is the ZIP+4 code for 63012?
63012 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 63012, you need to look up a specific street address to get them.
What city is 63012?
63012 is assigned to Barnhart, Missouri, 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.