ZIP Code 08831 — Monroe Township, NJ
08831 is a standard (street delivery) ZIP code serving Monroe Township, New Jersey, in Middlesex 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 08831 at a glance
| ZIP code | 08831 |
|---|---|
| Primary city | Monroe Township |
| State | New Jersey (NJ) |
| County | Middlesex FIPS 34023 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 55,658 |
| Coordinates | 40.329080, -74.430660 |
How ZIP+4 works in 08831
The four digits after the hyphen encode a delivery segment inside 08831. 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 08831 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 08831.
| ZIP | City | Distance |
|---|---|---|
| 08828 | Helmetta, NJ | 3.4 mi |
| 08810 | Dayton, NJ | 4.5 mi |
| 08884 | Spotswood, NJ | 5 mi |
| 08512 | Cranbury, NJ | 5 mi |
| 07726 | Englishtown, NJ | 5.6 mi |
| 08535 | Millstone Township, NJ | 6.5 mi |
| 08857 | Old Bridge, NJ | 6.8 mi |
| 08816 | East Brunswick, NJ | 7 mi |
| 08852 | Monmouth Junction, NJ | 7.3 mi |
| 08520 | Hightstown, NJ | 7.4 mi |
| 08555 | Roosevelt, NJ | 7.8 mi |
| 08536 | Plainsboro, NJ | 8.1 mi |
Questions about 08831
What is the ZIP+4 code for 08831?
08831 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 08831, you need to look up a specific street address to get them.
What city is 08831?
08831 is assigned to Monroe Township, New Jersey, in Middlesex 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.