ZIP Code 78631 — Harper, TX
78631 is a standard (street delivery) ZIP code serving Harper, Texas, in Kimble 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 78631 at a glance
| ZIP code | 78631 |
|---|---|
| Primary city | Harper |
| State | Texas (TX) |
| County | Kimble FIPS 48267 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 3,465 |
| Coordinates | 30.345760, -99.311610 |
How ZIP+4 works in 78631
The four digits after the hyphen encode a delivery segment inside 78631. 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 78631 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 78631.
| ZIP | City | Distance |
|---|---|---|
| 78618 | Doss, TX | 12.9 mi |
| 78025 | Ingram, TX | 18.4 mi |
| 76854 | London, TX | 20.6 mi |
| 78058 | Mountain Home, TX | 22.2 mi |
| 78028 | Kerrville, TX | 22.8 mi |
| 76856 | Mason, TX | 24.8 mi |
| 78024 | Hunt, TX | 26.3 mi |
| 78624 | Fredericksburg, TX | 26.5 mi |
| 78029 | Kerrville, TX | 31.5 mi |
| 76849 | Junction, TX | 32.3 mi |
| 78010 | Center Point, TX | 33.9 mi |
| 76820 | Art, TX | 34.7 mi |
Questions about 78631
What is the ZIP+4 code for 78631?
78631 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 78631, you need to look up a specific street address to get them.
What city is 78631?
78631 is assigned to Harper, Texas, in Kimble 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.