ZIP Code 94588 — Pleasanton, CA
94588 is a standard (street delivery) ZIP code serving Pleasanton, California, in Alameda 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 94588 at a glance
| ZIP code | 94588 |
|---|---|
| Primary city | Pleasanton |
| State | California (CA) |
| County | Alameda FIPS 06001 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Los_Angeles |
| Population | 34,328 |
| Coordinates | 37.738010, -121.881780 |
How ZIP+4 works in 94588
The four digits after the hyphen encode a delivery segment inside 94588. 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 94588 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.
Other ZIP codes in Pleasanton
Nearby ZIP codes
Showing the closest twelve. See every ZIP code within 25 miles of 94588.
| ZIP | City | Distance |
|---|---|---|
| 94568 | Dublin, CA | 1.9 mi |
| 94582 | San Ramon, CA | 2.5 mi |
| 94506 | Danville, CA | 5 mi |
| 94566 | Pleasanton, CA | 6.2 mi |
| 94583 | San Ramon, CA | 6.4 mi |
| 94551 | Livermore, CA | 6.8 mi |
| 94552 | Castro Valley, CA | 7.6 mi |
| 94526 | Danville, CA | 7.7 mi |
| 94528 | Diablo, CA | 8.3 mi |
| 94542 | Hayward, CA | 9.7 mi |
| 94507 | Alamo, CA | 10.5 mi |
| 94517 | Clayton, CA | 10.7 mi |
Questions about 94588
What is the ZIP+4 code for 94588?
94588 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 94588, you need to look up a specific street address to get them.
What city is 94588?
94588 is assigned to Pleasanton, California, in Alameda 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.