ZIP Code 99350 — Prosser, WA
99350 is a standard (street delivery) ZIP code serving Prosser, Washington, in Benton 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 99350 at a glance
| ZIP code | 99350 |
|---|---|
| Primary city | Prosser |
| State | Washington (WA) |
| County | Benton FIPS 53005 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Los_Angeles |
| Population | 14,837 |
| Coordinates | 46.144770, -119.709440 |
How ZIP+4 works in 99350
The four digits after the hyphen encode a delivery segment inside 99350. 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 99350 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 99350.
| ZIP | City | Distance |
|---|---|---|
| 98930 | Grandview, WA | 12.3 mi |
| 99345 | Paterson, WA | 14.6 mi |
| 99320 | Benton City, WA | 15.4 mi |
| 98935 | Mabton, WA | 17.2 mi |
| 99353 | West Richland, WA | 19.8 mi |
| 97844 | Irrigon, OR | 19.9 mi |
| 99346 | Plymouth, WA | 20.9 mi |
| 99338 | Kennewick, WA | 20.9 mi |
| 99352 | Richland, WA | 21.1 mi |
| 99354 | Richland, WA | 23.4 mi |
| 97882 | Umatilla, OR | 23.8 mi |
| 98944 | Sunnyside, WA | 24.6 mi |
Questions about 99350
What is the ZIP+4 code for 99350?
99350 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 99350, you need to look up a specific street address to get them.
What city is 99350?
99350 is assigned to Prosser, Washington, in Benton 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.