ZIP Code 03854 — New Castle, NH
03854 is a standard (street delivery) ZIP code serving New Castle, 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 03854 at a glance
| ZIP code | 03854 |
|---|---|
| Primary city | New Castle |
| State | New Hampshire (NH) |
| County | Rockingham FIPS 33015 |
| ZIP type | Standard (street delivery) |
| Time zone | America/New_York |
| Population | 827 |
| Coordinates | 43.065580, -70.720030 |
How ZIP+4 works in 03854
The four digits after the hyphen encode a delivery segment inside 03854. 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 03854 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 03854.
| ZIP | City | Distance |
|---|---|---|
| 03905 | Kittery Point, ME | 2.2 mi |
| 03904 | Kittery, ME | 3.1 mi |
| 03870 | Rye, NH | 4 mi |
| 03801 | Portsmouth, NH | 4.3 mi |
| 03911 | York Harbor, ME | 6.3 mi |
| 03871 | Rye Beach, NH | 6.4 mi |
| 03903 | Eliot, ME | 6.6 mi |
| 03840 | Greenland, NH | 6.7 mi |
| 03909 | York, ME | 7.3 mi |
| 03862 | North Hampton, NH | 8.2 mi |
| 03910 | York Beach, ME | 9.3 mi |
| 03885 | Stratham, NH | 9.7 mi |
Questions about 03854
What is the ZIP+4 code for 03854?
03854 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 03854, you need to look up a specific street address to get them.
What city is 03854?
03854 is assigned to New Castle, 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.