ZIP Code 83631 — Idaho City, ID
83631 is a standard (street delivery) ZIP code serving Idaho City, Idaho, in Boise 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 83631 at a glance
| ZIP code | 83631 |
|---|---|
| Primary city | Idaho City |
| State | Idaho (ID) |
| County | Boise FIPS 16015 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Boise |
| Population | 1,916 |
| Coordinates | 43.885430, -115.773690 |
How ZIP+4 works in 83631
The four digits after the hyphen encode a delivery segment inside 83631. 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 83631 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 83631.
| ZIP | City | Distance |
|---|---|---|
| 83666 | Placerville, ID | 11.3 mi |
| 83716 | Boise, ID | 15.8 mi |
| 83622 | Garden Valley, ID | 16.3 mi |
| 83629 | Horseshoe Bend, ID | 19.8 mi |
| 83602 | Banks, ID | 23.7 mi |
| 83702 | Boise, ID | 24.6 mi |
| 83712 | Boise, ID | 25.2 mi |
| 83714 | Garden City, ID | 27.1 mi |
| 83703 | Boise, ID | 27.8 mi |
| 83720 | Boise, ID | 28.1 mi |
| 83670 | Sweet, ID | 28.1 mi |
| 83725 | Boise, ID | 28.9 mi |
Questions about 83631
What is the ZIP+4 code for 83631?
83631 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 83631, you need to look up a specific street address to get them.
What city is 83631?
83631 is assigned to Idaho City, Idaho, in Boise 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.