ZIP Code 99166 — Republic, WA
99166 is a standard (street delivery) ZIP code serving Republic, Washington, in Ferry 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 99166 at a glance
| ZIP code | 99166 |
|---|---|
| Primary city | Republic |
| State | Washington (WA) |
| County | Ferry FIPS 53019 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Los_Angeles |
| Population | 2,953 |
| Coordinates | 48.610330, -118.671500 |
How ZIP+4 works in 99166
The four digits after the hyphen encode a delivery segment inside 99166. 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 99166 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 99166.
| ZIP | City | Distance |
|---|---|---|
| 99150 | Malo, WA | 13.8 mi |
| 98859 | Wauconda, WA | 17.6 mi |
| 99118 | Curlew, WA | 19.9 mi |
| 99141 | Kettle Falls, WA | 24 mi |
| 99160 | Orient, WA | 24.6 mi |
| 99121 | Danville, WA | 25 mi |
| 99155 | Nespelem, WA | 26.5 mi |
| 98855 | Tonasket, WA | 27.1 mi |
| 99167 | Rice, WA | 28.7 mi |
| 99138 | Inchelium, WA | 29.2 mi |
| 99146 | Laurier, WA | 29.4 mi |
| 99140 | Keller, WA | 32.8 mi |
Questions about 99166
What is the ZIP+4 code for 99166?
99166 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 99166, you need to look up a specific street address to get them.
What city is 99166?
99166 is assigned to Republic, Washington, in Ferry 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.