City · New Hampshire · United States
Newmarket, NH — ZIP codes
1 ZIP code · Rockingham County
- City
- Newmarket
- County
- Rockingham
- State
- New Hampshire
- Country
- United States
- Postal code
- 03857Single source
- Coordinates
- 43.0726, -70.9553 View on OpenStreetMap
- Area code
- 603
ZIP codes (1)
| Postal code | Place name | Verification |
|---|---|---|
| 03857 | Newmarket | Single source |
Sources and verification
US ZIP codes have five digits. They are postal routing areas, not administrative boundaries: a ZIP can span more than one city or county, and the city shown is the primary USPS name for that code.
GeoNames · U.S. Census Bureau (ACS). Last generated : 2026-08-21. Report an error.