ZIP Code 06231 — Amston, CT
06231 is a standard (street delivery) ZIP code serving Amston, Connecticut, in Capitol 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 06231 at a glance
| ZIP code | 06231 |
|---|---|
| Primary city | Amston |
| State | Connecticut (CT) |
| County | Capitol FIPS 09110 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 3,648 |
| Coordinates | 41.625120, -72.370550 |
How ZIP+4 works in 06231
The four digits after the hyphen encode a delivery segment inside 06231. 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 06231 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 06231.
| ZIP | City | Distance |
|---|---|---|
| 06447 | Marlborough, CT | 4.4 mi |
| 06248 | Hebron, CT | 4.5 mi |
| 06415 | Colchester, CT | 4.9 mi |
| 06237 | Columbia, CT | 5.8 mi |
| 06249 | Lebanon, CT | 6.7 mi |
| 06232 | Andover, CT | 7.5 mi |
| 06424 | East Hampton, CT | 8.3 mi |
| 06469 | Moodus, CT | 9.1 mi |
| 06336 | Gilman, CT | 9.6 mi |
| 06414 | Cobalt, CT | 9.9 mi |
| 06226 | Willimantic, CT | 10.2 mi |
| 06033 | Glastonbury, CT | 10.3 mi |
Questions about 06231
What is the ZIP+4 code for 06231?
06231 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 06231, you need to look up a specific street address to get them.
What city is 06231?
06231 is assigned to Amston, Connecticut, in Capitol 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.