ZIP Code 78634 — Hutto, TX
78634 is a standard (street delivery) ZIP code serving Hutto, Texas, in Williamson 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 78634 at a glance
| ZIP code | 78634 |
|---|---|
| Primary city | Hutto |
| State | Texas (TX) |
| County | Williamson FIPS 48491 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 46,413 |
| Coordinates | 30.560000, -97.544040 |
How ZIP+4 works in 78634
The four digits after the hyphen encode a delivery segment inside 78634. 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 78634 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 78634.
| ZIP | City | Distance |
|---|---|---|
| 78665 | Round Rock, TX | 5.6 mi |
| 78664 | Round Rock, TX | 7.2 mi |
| 78626 | Georgetown, TX | 8 mi |
| 78674 | Weir, TX | 8.3 mi |
| 78660 | Pflugerville, TX | 8.6 mi |
| 76574 | Taylor, TX | 9.3 mi |
| 78681 | Round Rock, TX | 10.6 mi |
| 78615 | Coupland, TX | 11.3 mi |
| 78728 | Austin, TX | 11.3 mi |
| 76530 | Granger, TX | 12.8 mi |
| 78628 | Georgetown, TX | 13.2 mi |
| 78717 | Austin, TX | 13.4 mi |
Questions about 78634
What is the ZIP+4 code for 78634?
78634 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 78634, you need to look up a specific street address to get them.
What city is 78634?
78634 is assigned to Hutto, Texas, in Williamson 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.