ZIP Code 99110 — Clayton, WA
99110 is a standard (street delivery) ZIP code serving Clayton, Washington, in Stevens 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 99110 at a glance
| ZIP code | 99110 |
|---|---|
| Primary city | Clayton |
| State | Washington (WA) |
| County | Stevens FIPS 53065 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Los_Angeles |
| Population | 1,505 |
| Coordinates | 48.008300, -117.581120 |
How ZIP+4 works in 99110
The four digits after the hyphen encode a delivery segment inside 99110. 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 99110 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 99110.
| ZIP | City | Distance |
|---|---|---|
| 99006 | Deer Park, WA | 5.1 mi |
| 99148 | Loon Lake, WA | 6.9 mi |
| 99034 | Tumtum, WA | 11.9 mi |
| 99181 | Valley, WA | 12.7 mi |
| 99173 | Springdale, WA | 12.9 mi |
| 99026 | Nine Mile Falls, WA | 14.3 mi |
| 99013 | Ford, WA | 14.5 mi |
| 99005 | Colbert, WA | 15.1 mi |
| 99003 | Chattaroy, WA | 15.3 mi |
| 99009 | Elk, WA | 15.3 mi |
| 99208 | Spokane, WA | 16.6 mi |
| 99218 | Spokane, WA | 19 mi |
Questions about 99110
What is the ZIP+4 code for 99110?
99110 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 99110, you need to look up a specific street address to get them.
What city is 99110?
99110 is assigned to Clayton, Washington, in Stevens 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.