Area Code 603 is for people calling from the State of New Hampshire in the United States. This area code is designated entirely to the state of NH. The 603 area code was designated as part of the North American Numbering Plan (NANP for short).
Where is 603 area code?
Anyone calling from the 603 area code is calling from the state of New Hampshire. That area code is dedicated solely for the state of NH. New Hampshire resides in the Eastern Time Zone. To see the current time in NH visit here.
History of The 603 Area Code For New Hampshire
The 603 area code was part of the original plan created by AT&T and the Bell System back in the year 1947. The system has evolved over the years but the state of NH is still associated with the 603 area code so when you see that show up in a phone call that person is calling from New Hampshire.
Towns and Cities In New Hampshire
To see a full list of cities and towns in New Hampshire visit this page.