ZIP Code 83420 — Ashton, ID
83420 is a standard (street delivery) ZIP code serving Ashton, Idaho, in Fremont 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 83420 at a glance
| ZIP code | 83420 |
|---|---|
| Primary city | Ashton |
| State | Idaho (ID) |
| County | Fremont FIPS 16043 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Boise |
| Population | 2,580 |
| Coordinates | 44.060010, -111.322430 |
How ZIP+4 works in 83420
The four digits after the hyphen encode a delivery segment inside 83420. 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 83420 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 83420.
| ZIP | City | Distance |
|---|---|---|
| 83421 | Chester, ID | 11.5 mi |
| 83424 | Felt, ID | 12.5 mi |
| 83436 | Newdale, ID | 15.6 mi |
| 83452 | Tetonia, ID | 16.4 mi |
| 83445 | Saint Anthony, ID | 20.3 mi |
| 83451 | Teton, ID | 20.5 mi |
| 83414 | Alta, WY | 22 mi |
| 83438 | Parker, ID | 22.7 mi |
| 83448 | Sugar City, ID | 23.8 mi |
| 83422 | Driggs, ID | 24.9 mi |
| 83460 | Rexburg, ID | 28.3 mi |
| 83440 | Rexburg, ID | 29.6 mi |
Questions about 83420
What is the ZIP+4 code for 83420?
83420 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 83420, you need to look up a specific street address to get them.
What city is 83420?
83420 is assigned to Ashton, Idaho, in Fremont 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.