ZIP Code 78590 — San Perlita, TX
78590 is a standard (street delivery) ZIP code serving San Perlita, Texas, in Willacy 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 78590 at a glance
| ZIP code | 78590 |
|---|---|
| Primary city | San Perlita |
| State | Texas (TX) |
| County | Willacy FIPS 48489 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Chicago |
| Population | 428 |
| Coordinates | 26.504010, -97.634860 |
How ZIP+4 works in 78590
The four digits after the hyphen encode a delivery segment inside 78590. 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 78590 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 78590.
| ZIP | City | Distance |
|---|---|---|
| 78580 | Raymondville, TX | 7.2 mi |
| 78569 | Lyford, TX | 11 mi |
| 78598 | Port Mansfield, TX | 13.1 mi |
| 78594 | Sebastian, TX | 15 mi |
| 78550 | Harlingen, TX | 17.3 mi |
| 78561 | Lasara, TX | 17.5 mi |
| 78583 | Rio Hondo, TX | 18.5 mi |
| 78535 | Combes, TX | 18.5 mi |
| 78593 | Santa Rosa, TX | 19.9 mi |
| 78562 | La Villa, TX | 21.8 mi |
| 78540 | Edinburg, TX | 22.2 mi |
| 78552 | Harlingen, TX | 22.4 mi |
Questions about 78590
What is the ZIP+4 code for 78590?
78590 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 78590, you need to look up a specific street address to get them.
What city is 78590?
78590 is assigned to San Perlita, Texas, in Willacy 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.