ZIP Code 99343 — Mesa, WA
99343 is a standard (street delivery) ZIP code serving Mesa, Washington, in Franklin 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 99343 at a glance
| ZIP code | 99343 |
|---|---|
| Primary city | Mesa |
| State | Washington (WA) |
| County | Franklin FIPS 53021 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Los_Angeles |
| Population | 3,215 |
| Coordinates | 46.591880, -119.170650 |
How ZIP+4 works in 99343
The four digits after the hyphen encode a delivery segment inside 99343. 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 99343 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 99343.
| ZIP | City | Distance |
|---|---|---|
| 99330 | Eltopia, WA | 9.5 mi |
| 99344 | Othello, WA | 15.9 mi |
| 99326 | Connell, WA | 16.6 mi |
| 99301 | Pasco, WA | 17.8 mi |
| 99354 | Richland, WA | 19 mi |
| 99353 | West Richland, WA | 21.4 mi |
| 98944 | Sunnyside, WA | 24.3 mi |
| 99352 | Richland, WA | 24.8 mi |
| 99320 | Benton City, WA | 24.8 mi |
| 99336 | Kennewick, WA | 26.1 mi |
| 99349 | Mattawa, WA | 26.8 mi |
| 98857 | Warden, WA | 28 mi |
Questions about 99343
What is the ZIP+4 code for 99343?
99343 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 99343, you need to look up a specific street address to get them.
What city is 99343?
99343 is assigned to Mesa, Washington, in Franklin 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.