ZIP Code 63042 — Hazelwood, MO
63042 is a standard (street delivery) ZIP code serving Hazelwood, 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 63042 at a glance
| ZIP code | 63042 |
|---|---|
| Primary city | Hazelwood |
| State | Missouri (MO) |
| County | St. Louis FIPS 29189 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 17,813 |
| Coordinates | 38.781330, -90.379090 |
How ZIP+4 works in 63042
The four digits after the hyphen encode a delivery segment inside 63042. 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 63042 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 63042.
| ZIP | City | Distance |
|---|---|---|
| 63044 | Bridgeton, MO | 2.7 mi |
| 63031 | Florissant, MO | 2.7 mi |
| 63134 | Saint Louis, MO | 3.2 mi |
| 63074 | Saint Ann, MO | 3.8 mi |
| 63140 | Saint Louis, MO | 4.1 mi |
| 63045 | Earth City, MO | 4.7 mi |
| 63135 | Saint Louis, MO | 4.8 mi |
| 63114 | Saint Louis, MO | 5.5 mi |
| 63033 | Florissant, MO | 5.5 mi |
| 63043 | Maryland Heights, MO | 5.5 mi |
| 63121 | Saint Louis, MO | 6.6 mi |
| 63034 | Florissant, MO | 6.8 mi |
Questions about 63042
What is the ZIP+4 code for 63042?
63042 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 63042, you need to look up a specific street address to get them.
What city is 63042?
63042 is assigned to Hazelwood, 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.