ZIP Code 63033 — Florissant, MO
63033 is a standard (street delivery) ZIP code serving Florissant, Missouri, in St. Louis 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 63033 at a glance
| ZIP code | 63033 |
|---|---|
| Primary city | Florissant |
| State | Missouri (MO) |
| County | St. Louis FIPS 29189 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 43,056 |
| Coordinates | 38.795800, -90.277860 |
How ZIP+4 works in 63033
The four digits after the hyphen encode a delivery segment inside 63033. 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 63033 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.
Other ZIP codes in Florissant
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 63033.
| ZIP | City | Distance |
|---|---|---|
| 63135 | Saint Louis, MO | 3.4 mi |
| 63034 | Florissant, MO | 3.6 mi |
| 63136 | Saint Louis, MO | 3.7 mi |
| 63031 | Florissant, MO | 4.2 mi |
| 63140 | Saint Louis, MO | 4.6 mi |
| 63137 | Saint Louis, MO | 4.7 mi |
| 63138 | Saint Louis, MO | 5.1 mi |
| 63134 | Saint Louis, MO | 5.1 mi |
| 63042 | Hazelwood, MO | 5.5 mi |
| 63386 | West Alton, MO | 6.1 mi |
| 63121 | Saint Louis, MO | 6.2 mi |
| 63120 | Saint Louis, MO | 7.3 mi |
Questions about 63033
What is the ZIP+4 code for 63033?
63033 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 63033, you need to look up a specific street address to get them.
What city is 63033?
63033 is assigned to Florissant, Missouri, in St. Louis 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.