ZIP Code 11731 — East Northport, NY
11731 is a standard (street delivery) ZIP code serving East Northport, New York, in Suffolk 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 11731 at a glance
| ZIP code | 11731 |
|---|---|
| Primary city | East Northport |
| State | New York (NY) |
| County | Suffolk FIPS 36103 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 29,999 |
| Coordinates | 40.862620, -73.317030 |
How ZIP+4 works in 11731
The four digits after the hyphen encode a delivery segment inside 11731. 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 11731 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 11731.
| ZIP | City | Distance |
|---|---|---|
| 11740 | Greenlawn, NY | 2.3 mi |
| 11725 | Commack, NY | 2.4 mi |
| 11768 | Northport, NY | 3.3 mi |
| 11721 | Centerport, NY | 3.5 mi |
| 11746 | Huntington Station, NY | 4 mi |
| 11754 | Kings Park, NY | 4 mi |
| 11787 | Smithtown, NY | 5.6 mi |
| 11743 | Huntington, NY | 5.8 mi |
| 11788 | Hauppauge, NY | 6.2 mi |
| 11717 | Brentwood, NY | 6.4 mi |
| 11729 | Deer Park, NY | 6.9 mi |
| 11724 | Cold Spring Harbor, NY | 7.1 mi |
Questions about 11731
What is the ZIP+4 code for 11731?
11731 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 11731, you need to look up a specific street address to get them.
What city is 11731?
11731 is assigned to East Northport, New York, in Suffolk 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.