ZIP Code 81120 — Antonito, CO
81120 is a standard (street delivery) ZIP code serving Antonito, Colorado, in Conejos 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 81120 at a glance
| ZIP code | 81120 |
|---|---|
| Primary city | Antonito |
| State | Colorado (CO) |
| County | Conejos FIPS 08021 |
| ZIP type | Standard (street delivery) |
| Time zone | America/Denver |
| Population | 1,832 |
| Coordinates | 37.142480, -106.267150 |
How ZIP+4 works in 81120
The four digits after the hyphen encode a delivery segment inside 81120. 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 81120 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 81120.
| ZIP | City | Distance |
|---|---|---|
| 81140 | La Jara, CO | 11.7 mi |
| 81124 | Capulin, CO | 13.2 mi |
| 81129 | Conejos, CO | 13.7 mi |
| 81148 | Romeo, CO | 15.6 mi |
| 81141 | Manassa, CO | 20.5 mi |
| 81128 | Chromo, CO | 21.8 mi |
| 87520 | Chama, NM | 27 mi |
| 81144 | Monte Vista, CO | 29 mi |
| 81151 | Sanford, CO | 31 mi |
| 81101 | Alamosa, CO | 32.2 mi |
| 87551 | Los Ojos, NM | 38.1 mi |
| 81154 | South Fork, CO | 40.6 mi |
Questions about 81120
What is the ZIP+4 code for 81120?
81120 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 81120, you need to look up a specific street address to get them.
What city is 81120?
81120 is assigned to Antonito, Colorado, in Conejos 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.