ZIP Code 06820 — Darien, CT
06820 is a standard (street delivery) ZIP code serving Darien, Connecticut, in Western Connecticut 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 06820 at a glance
| ZIP code | 06820 |
|---|---|
| Primary city | Darien |
| State | Connecticut (CT) |
| County | Western Connecticut FIPS 09190 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 21,936 |
| Coordinates | 41.079830, -73.482420 |
How ZIP+4 works in 06820
The four digits after the hyphen encode a delivery segment inside 06820. 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 06820 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 06820.
| ZIP | City | Distance |
|---|---|---|
| 06906 | Stamford, CT | 2.1 mi |
| 06853 | Norwalk, CT | 2.4 mi |
| 06907 | Stamford, CT | 2.5 mi |
| 06854 | Norwalk, CT | 2.9 mi |
| 06905 | Stamford, CT | 3.2 mi |
| 06901 | Stamford, CT | 3.4 mi |
| 06902 | Stamford, CT | 3.7 mi |
| 06850 | Norwalk, CT | 3.8 mi |
| 06855 | Norwalk, CT | 4.5 mi |
| 06840 | New Canaan, CT | 5.5 mi |
| 06870 | Old Greenwich, CT | 5.7 mi |
| 06851 | Norwalk, CT | 5.8 mi |
Questions about 06820
What is the ZIP+4 code for 06820?
06820 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 06820, you need to look up a specific street address to get them.
What city is 06820?
06820 is assigned to Darien, Connecticut, in Western Connecticut 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.