ZIP Code 78738 — Austin, TX
78738 is a standard (street delivery) ZIP code serving Austin, Texas, in Travis 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 78738 at a glance
| ZIP code | 78738 |
|---|---|
| Primary city | Austin |
| State | Texas (TX) |
| County | Travis FIPS 48453 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 31,019 |
| Coordinates | 30.306680, -97.990020 |
How ZIP+4 works in 78738
The four digits after the hyphen encode a delivery segment inside 78738. 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 78738 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 Austin
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 78738.
| ZIP | City | Distance |
|---|---|---|
| 78736 | Austin, TX | 4.7 mi |
| 78734 | Austin, TX | 5.7 mi |
| 78733 | Austin, TX | 6.8 mi |
| 78732 | Austin, TX | 7.7 mi |
| 78735 | Austin, TX | 7.8 mi |
| 78737 | Austin, TX | 8.3 mi |
| 78730 | Austin, TX | 9.8 mi |
| 78645 | Leander, TX | 10 mi |
| 78749 | Austin, TX | 10.2 mi |
| 78620 | Dripping Springs, TX | 10.4 mi |
| 78746 | Austin, TX | 10.7 mi |
| 78739 | Austin, TX | 10.8 mi |
Questions about 78738
What is the ZIP+4 code for 78738?
78738 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 78738, you need to look up a specific street address to get them.
What city is 78738?
78738 is assigned to Austin, Texas, in Travis 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.