603 area code
Area code 603 is in New Hampshire. It covers Manchester, Nashua, Concord and 260 other places: 281 ZIP codes in Hillsborough, Rockingham, Merrimack and 8 other counties. Local time there is , Eastern Time. In service since 1947, with no overlay.
- State
- New Hampshire
- Time zone
- Eastern
- Largest city
- Manchester
- Overlays
- none
- In service since
- 1947
- Rate centres
- 147
- Prefixes assigned
- 752 (7,520,000 numbers)
Who calls from a 603 number
NANPA records the carrier each block of 603 numbers is assigned to. Of the 6.6 million 603 numbers assigned, 36% are with mobile carriers (Verizon Wireless, T-Mobile and AT&T Mobility); 34% with cable, internet-calling, business and other carriers (PAETEC (Windstream) and Comcast); 30% with local phone companies (Consolidated Comm Of No. New England).
That is who the numbers were assigned to: people keep their number when they change carrier, so any one number may have moved since.
| Carrier | Kind | Share |
|---|---|---|
| Consolidated Comm Of No. New England | Landline | 28% |
| Verizon Wireless | Mobile | 16% |
| T-Mobile | Mobile | 9% |
| AT&T Mobility | Mobile | 7% |
| PAETEC (Windstream) | Cable, VoIP, other | 7% |
| Comcast | Cable, VoIP, other | 4% |
An area code says where a number was issued, not where the caller is: people keep their numbers when they move, and caller ID can be set to show any number, which the FCC calls spoofing. If a call you did not expect asks for money or personal details, the FCC advises hanging up and calling the company back on a number you look up yourself. Unwanted calls can be reported to the FTC at ReportFraud.ftc.gov.
Places in area code 603
The 139 places with a telephone rate centre of their own using 603, largest first. Each links to its ZIP codes.
Nearby places using 603
These places have no rate centre of their own in NANPA's records; the nearest one uses 603. Near an area-code boundary that can be wrong for part of a town.
- Windham
- Londonderry
- Litchfield
- Bow
- Gilford
- Stratham
- Hudson
- Atkinson
- Sandown
- Swanzey
- Auburn
- South Hooksett
- Hooksett
- Brookline
- Nottingham
- New Ipswich
- Rye
- Moultonborough
- East Merrimack
- Newton
- Fremont
- North Hampton
- Lee
- Danville
- Pinardville
- Strafford
- Center Conway
- Greenland
- Grantham
- East Kingston
- Tilton Northfield
- Sanbornton
- Thornton
- Mont Vernon
- East Hampstead
- Hampton Beach
- Gilmanton
- Rollinsford
- Hampton Falls
- Alton Bay
- Madbury
- Ossipee
- Newbury
- Holderness
- Effingham
- Cornish
- Hillsborough
- Center Tuftonboro
- Lyndeborough
- Freedom
- Wilmot
- East Wakefield
- Temple
- Grafton
- West Swanzey
- Intervale
- Hebron
- Etna
- Bath
- Chocorua
ZIP codes in area code 603
281 ZIP codes in 253 towns, by the town each is mailed to, largest first. Each links to its own page.
Where 603 numbers are issued
NANPA's rate centres with the most 603 prefixes (each prefix is 10,000 numbers), under NANPA's own abbreviated names.
| Rate centre | Place | Prefixes |
|---|---|---|
MANCHESTER | Manchester | 80 |
NASHUA | Nashua | 58 |
CONCORD | Concord | 39 |
DERRY | Derry | 29 |
DOVER | Dover | 29 |
PORTSMOUTH | Portsmouth | 28 |
Counties
The counties of its ZIP codes, most residents first, with how many of its ZIP codes each has.
- Hillsborough County (39)
- Rockingham County (44)
- Merrimack County (31)
- Strafford County (20)
- Grafton County (39)
- Cheshire County (27)
- Belknap County (18)
- Carroll County (30)
- Sullivan County (17)
- Coos County (15)
- Oxford County (1)
Which code covers where you are now? What area code am I in? answers from your location.
Questions about area code 603
Where is area code 603?
Area code 603 is in New Hampshire. It covers Manchester, Nashua, Concord and 260 other places: 281 ZIP codes in Hillsborough, Rockingham, Merrimack and 8 other counties.
What ZIP codes are in area code 603?
281 ZIP codes, by the town each is mailed to: Manchester (8, 03101 to 03111), Nashua (5, 03060 to 03064), Concord (4, 03301 to 03305), Dover (3, 03820 to 03822) and 249 more towns. The full list is on this page.
What time zone is area code 603 in?
Eastern time.
Is a 603 number a mobile or a landline?
It can be either. 36% of 603 numbers are assigned to mobile carriers and 30% to local phone companies (NANPA, 2026-10-10); the rest are with cable, internet-calling, business and paging carriers. A number keeps its area code when it moves to another carrier.
Does a 603 number mean the caller is in New Hampshire?
Not necessarily. An area code says where the number was first issued. People keep their numbers when they move or switch carriers, and calling software can show any number, so a 603 call can come from anywhere.
All 1 New Hampshire area codes, by area, with the cities each covers
Source: NANPA NPA database, central office code and thousands-block assignments, 2026-10-10. Places are matched to NANPA's rate centres by name; see sources.
Cite this page
zipcodes.pro. “Area code 603.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/area-code/603
Underlying data is public domain or openly licensed — sources, vintages and licences.