Area code 603

Area code 603 is the sole area code for the U.S. state of New Hampshire in the North American Numbering Plan (NANP). The numbering plan area (NPA) was created as one of the original 86 in October 1947.

As of April 2011, the 603 code was nearing exhaustion and a second area code for New Hampshire was expected to be activated by 2013. Rather than a split, the New Hampshire Public Utilities Commission recommended that it be implemented as a statewide overlay. However, because of a change in allocation policies and a reclamation of a large block of previously allocated telephone numbers, the exhaustion time frame has been moved beyond 2025.

Since New Hampshire has only one area code, callers in the state can reach any other telephone within the 603 area code with 7-digit dialing.

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