As of April 2011, area code 603 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 plan. As a result of changes in allocation policies and a reclamation of a large block of previously allocated telephone numbers, including number pooling, the exhaustion time frame has been moved to at least 2032.
Since New Hampshire has only one area code, callers in the state can reach any other telephone within the state via seven-digit dialing.
- "Archived copy". Archived from the original on September 29, 2011. Retrieved November 20, 2010.CS1 maint: archived copy as title (link)
- Dave Brooks (18 May 2016). "Area code 603 will reign supreme thanks to technology". The Concord Monitor. Retrieved 17 March 2019.
- NANPA area code map of New Hampshire
- List of exchanges from AreaCodeDownload.com, 603 Area Code
- December 2010 newspaper article about then-uncertain future of 603
|West: 802||area code 603||East: 207|
|South: 351/978, 413|
|Massachusetts area codes: 339/781, 351/978, 413, 508/774, 617/857|
|Maine area codes: 207|
|Quebec area codes: 367/418/581, 438/514, 450/579, 819/873|
|Vermont area codes: 802|