ZIP Code 78340 — Bayside, TX
78340 is a standard (street delivery) ZIP code serving Bayside, Texas, in Refugio 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 78340 at a glance
| ZIP code | 78340 |
|---|---|
| Primary city | Bayside |
| State | Texas (TX) |
| County | Refugio FIPS 48391 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 455 |
| Coordinates | 28.124720, -97.209820 |
How ZIP+4 works in 78340
The four digits after the hyphen encode a delivery segment inside 78340. 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 78340 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 78340.
| ZIP | City | Distance |
|---|---|---|
| 78382 | Rockport, TX | 8.9 mi |
| 78393 | Woodsboro, TX | 9.6 mi |
| 78358 | Fulton, TX | 10.9 mi |
| 78390 | Taft, TX | 12.3 mi |
| 78336 | Aransas Pass, TX | 12.6 mi |
| 78359 | Gregory, TX | 14.5 mi |
| 78377 | Refugio, TX | 15.1 mi |
| 78374 | Portland, TX | 17.1 mi |
| 78362 | Ingleside, TX | 17.8 mi |
| 78387 | Sinton, TX | 21.1 mi |
| 77950 | Austwell, TX | 21.4 mi |
| 78402 | Corpus Christi, TX | 24 mi |
Questions about 78340
What is the ZIP+4 code for 78340?
78340 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 78340, you need to look up a specific street address to get them.
What city is 78340?
78340 is assigned to Bayside, Texas, in Refugio 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.