Where Is Area Code 603?
Area code 603 serves the entire state of New Hampshire, which is in the New England region of the United States. Dover, the primary city associated with 603, is in Strafford County in southeastern New Hampshire. The code also covers Manchester, Nashua, Concord, Portsmouth, Rochester, Keene, and other communities.
Coverage includes all 10 New Hampshire counties: Belknap, Carroll, Cheshire, Coos, Grafton, Hillsborough, Merrimack, Rockingham, Strafford, and Sullivan. The 603 region includes the Atlantic Seacoast, the Lakes Region around Lake Winnipesaukee, the Merrimack River Valley, and the White Mountains. Mount Washington is in the northern part of this area.
Cities and Communities in the 603 Area Code
- Berlin, Coos County
- Claremont, Sullivan County
- Concord, Merrimack County
- Dover, Strafford County
- Franklin, Merrimack County
- Keene, Cheshire County
- Laconia, Belknap County
- Lebanon, Grafton County
- Manchester, Hillsborough County
- Nashua, Hillsborough County
- Portsmouth, Rockingham County
- Rochester, Strafford County
- Somersworth, Strafford County
- Alton, Belknap County
- Amherst, Hillsborough County
- Bedford, Hillsborough County
- Conway, Carroll County
- Derry, Rockingham County
- Durham, Strafford County
- Exeter, Rockingham County
- Gilford, Belknap County
- Hampton, Rockingham County
- Hanover, Grafton County
- Hollis, Hillsborough County
- Hudson, Hillsborough County
- Lincoln, Grafton County
- Londonderry, Rockingham County
- Meredith, Belknap County
- Merrimack, Hillsborough County
- Milford, Hillsborough County
- Newmarket, Rockingham County
- North Hampton, Rockingham County
- Peterborough, Hillsborough County
- Plymouth, Grafton County
- Rye, Rockingham County
- Salem, Rockingham County
- Windham, Rockingham County
- Wolfeboro, Carroll County
History of Area Code 603
Area code 603 was assigned to New Hampshire in 1947 as part of the original North American Numbering Plan. It was not created by splitting an older New Hampshire area code because the state had one statewide code from the plan’s beginning.
New Hampshire kept 603 as its statewide code while landline, mobile, and other telephone services expanded. The New Hampshire Public Utilities Commission approved a 975 overlay for the same geographic region to provide additional numbers. An overlay adds another code to the same area, so it does not divide New Hampshire or change existing 603 numbers.
Key Facts About Area Code 603
- State and region: Area code 603 is in New Hampshire, a state in the New England region.
- Primary city: Dover is the primary city associated with area code 603.
- Geographic scope: Area code 603 covers the entire state of New Hampshire.
- Population: New Hampshire had 1,377,529 residents in the 2020 U.S. Census.
- Type: Area code 603 is a geographic area code, not a toll-free code.
- Original assignment: The North American Numbering Plan assigned area code 603 in 1947.
- Time zone: The 603 region uses Eastern Time.
- Institutions and landmarks: The University of New Hampshire is in Durham, Dartmouth College is in Hanover, and Mount Washington is in Coos County.
Frequently Asked Questions
What state is area code 603 in?
Area code 603 is in New Hampshire.
What major cities use area code 603?
Major cities using area code 603 include Dover, Manchester, Nashua, Concord, Portsmouth, Rochester, Keene, Laconia, Lebanon, Berlin, Claremont, Franklin, and Somersworth.
What time zone is area code 603 in?
Area code 603 is in Eastern Time.
Is area code 603 a toll-free number?
No. Area code 603 is a geographic area code for New Hampshire, not a toll-free code.