ZIP Code 73521 — Altus, OK
73521 is a standard (street delivery) ZIP code serving Altus, Oklahoma, in Jackson 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 73521 at a glance
| ZIP code | 73521 |
|---|---|
| Primary city | Altus |
| State | Oklahoma (OK) |
| County | Jackson FIPS 40065 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 20,155 |
| Coordinates | 34.635470, -99.315380 |
How ZIP+4 works in 73521
The four digits after the hyphen encode a delivery segment inside 73521. 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 73521 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 73521.
| ZIP | City | Distance |
|---|---|---|
| 73523 | Altus Afb, OK | 2.2 mi |
| 73556 | Martha, OK | 7.5 mi |
| 73549 | Headrick, OK | 9.1 mi |
| 73560 | Olustee, OK | 10 mi |
| 73526 | Blair, OK | 11.2 mi |
| 73539 | Elmer, OK | 12.8 mi |
| 73570 | Tipton, OK | 14.7 mi |
| 73532 | Duke, OK | 16 mi |
| 79247 | Odell, TX | 16.9 mi |
| 73566 | Snyder, OK | 21.2 mi |
| 73555 | Manitou, OK | 21.9 mi |
| 73559 | Mountain Park, OK | 22.2 mi |
Questions about 73521
What is the ZIP+4 code for 73521?
73521 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 73521, you need to look up a specific street address to get them.
What city is 73521?
73521 is assigned to Altus, Oklahoma, in Jackson 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.