ZIP Code 03858 — Newton, NH
03858 is a standard (street delivery) ZIP code serving Newton, New Hampshire, in Rockingham 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 03858 at a glance
| ZIP code | 03858 |
|---|---|
| Primary city | Newton |
| State | New Hampshire (NH) |
| County | Rockingham FIPS 33015 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 4,836 |
| Coordinates | 42.868390, -71.043570 |
How ZIP+4 works in 03858
The four digits after the hyphen encode a delivery segment inside 03858. 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 03858 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 03858.
| ZIP | City | Distance |
|---|---|---|
| 01860 | Merrimac, MA | 2.6 mi |
| 03865 | Plaistow, NH | 3.3 mi |
| 03848 | Kingston, NH | 3.5 mi |
| 03827 | East Kingston, NH | 3.9 mi |
| 03826 | East Hampstead, NH | 4.5 mi |
| 01830 | Haverhill, MA | 5 mi |
| 01913 | Amesbury, MA | 5.1 mi |
| 03819 | Danville, NH | 5.8 mi |
| 03811 | Atkinson, NH | 6.3 mi |
| 01985 | West Newbury, MA | 6.4 mi |
| 01832 | Haverhill, MA | 6.9 mi |
| 03841 | Hampstead, NH | 6.9 mi |
Questions about 03858
What is the ZIP+4 code for 03858?
03858 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 03858, you need to look up a specific street address to get them.
What city is 03858?
03858 is assigned to Newton, New Hampshire, in Rockingham 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.