603 Area Code belongs to the New Hampshire (NH) State.
Other cities in the 603 Area Code.
Amherst, Atkinson, Barrington, Bedford, Berlin, Claremont, Concord, Derry, Dover, Durham, Goffstown, Hampton, Hanover, Hooksett, Keene, Laconia, Lebanon, Londonderry, Manchester, Merrimack, Milford, Nashua, Pelham, Portsmouth, Raymond, Rochester, Salem, Windham
New Hampshire (NH)
also shares with these area codes: