ZIP Code 76831 — Castell, TX
76831 is a standard (street delivery) ZIP code serving Castell, Texas, in Llano 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 76831 at a glance
| ZIP code | 76831 |
|---|---|
| Primary city | Castell |
| State | Texas (TX) |
| County | Llano FIPS 48299 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Coordinates | 30.745990, -98.955430 |
How ZIP+4 works in 76831
The four digits after the hyphen encode a delivery segment inside 76831. 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 76831 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 76831.
| ZIP | City | Distance |
|---|---|---|
| 76820 | Art, TX | 6.2 mi |
| 76885 | Valley Spring, TX | 10.5 mi |
| 76869 | Pontotoc, TX | 11.3 mi |
| 76842 | Fredonia, TX | 14.8 mi |
| 78643 | Llano, TX | 15.1 mi |
| 76856 | Mason, TX | 18.7 mi |
| 76832 | Cherokee, TX | 20.2 mi |
| 78618 | Doss, TX | 21.9 mi |
| 76887 | Voca, TX | 22.8 mi |
| 78675 | Willow City, TX | 24.8 mi |
| 78607 | Bluffton, TX | 28.2 mi |
| 78672 | Tow, TX | 29.1 mi |
Questions about 76831
What is the ZIP+4 code for 76831?
76831 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 76831, you need to look up a specific street address to get them.
What city is 76831?
76831 is assigned to Castell, Texas, in Llano 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.