Area code 603 will reign supreme in New Hampshire thanks to technology

  • 603 Brewery is one of many New Hampshire companies that use the state’s area code in its name. David Brooks/ Monitor staff

Monitor staff
Published: 5/18/2016 1:50:33 AM

Seventeen years ago, news swept through New Hampshire that galvanized opposition from every corner of the state. People howled in outrage as they scrambled to protect an aspect of Granite State life they held near and dear: the area code.

603 has been the lead-in to all telephone numbers in New Hampshire since area codes were developed in 1947. It is so ingrained that at least 134 companies use it as part of their name, according to listings at the New Hampshire Corporation Division, ranging from a lounge in Nashua to a Concord basketball training firm to something called 603 Strippers to a microbrewery in Londonderry.

“Everybody who comes in knows 603 is our area code. The connection is immediate,” said David Moses, a cashier at Capital Beverages on South Main Street in Concord, as he showed the store’s selection of beers from 603 Brewery.

Happily, that connection will remain. The N.H. Public Utilities Commission said Tuesday that the organization that oversees telephone numbers has confirmed that 603 will remain our only area code for at least another 16 years.

This is actually an improvement. The last time the North American Numbering Plan Administrator, or NANPA, discussed the issue, it said 603 might run out of room by 2020, but on Monday, it said the area code could remain solo until 2032.

The reason for the extension is technical, as is the reason why 603 was imperiled even though it contains far more phone numbers than New Hampshire has people. After all, between 111-1111 and 999-9999 there are almost 10 million possible numbers, surely enough for 1.4 million residents.

The shortage stems largely from the way the telephone system was built decades ago.

Landline phones were built on circuit-switched networks, in which each phone call occupies an entire line all the way from one person to another. Originally human operators made sure the line was connected end-to-end, putting the right plugs into the right switchboard holes, but as long-distance networks expanded and automatic switches were developed, a new system was needed so machines would know where to direct out-of-state calls.

That system turned out to be three-digit area codes, which were assigned throughout the U.S. and Canada by geography as part of the post-World War II boom.

The codes were handed out to places based on population, with bigger places getting codes that added up to fewer digits as a way to minimize total usage of the network. New York City got the best area code of 212, which totals up to only five, because it was biggest city; then came Chicago (312) and Los Angeles (213). (No code could start with a “1”, which was used to signal a long-distance call.) 

New Hampshire’s code, 603, totals 19 digits (counting 0 as 10), indicating how small our population is. Vermont’s code of 802, totaling 20 digits, indicates that it is even smaller.

As a side note, the fact that the middle digit is “0” also indicates something: that our area code covers an entire state. States with multiple area codes got numbers with “1” in the middle, such as 617 around Boston.

Inside each area code, seven-digit phone numbers were handed out based on three-digit exchanges that covered smaller areas, such as 225 in Concord, followed by four digits. And this is where the problem arose. 

Four digits equals 9,999 possible phone numbers for each exchange, but because of limits with switching systems located in central offices, those numbers had to be assigned all-or-nothing, even if there weren’t 9,999 customers waiting to get a new phone. As a result, many phone numbers were unused, sitting vacant because not enough customers existed within a given exchange.

This situation triggered NANPA’s announcement in 1999. There were lots of available phone numbers within the 603 area code but too many were inaccessible, trapped inside exchanges that didn’t have enough need for them.

The alarm set off by NANPA’s warning led PUC staff to push for alternatives, however, and in coming years the deadline for an overly full 603 kept getting pushed back as methods were found to better divvy up exchanges as part of transition to digital switching.

By 2010, the system had improved so much that NANPA said we were safe through 2015; the following year, they said we were safe through 2020. And now we’re safe through at least 2032.

The safety is partially a reflection of our slow growth. Despite technical improvements, other places are getting new area codes this year, including Manhattan and coastal South Carolina, and other codes are imperiled, such as 717 in southern Pennsylvania.

It may also reflect cell phones and voice-over-internet calling, which have scrambled the situation because they are not linked to geography and thus can bypass shortages, at least in theory.

But whatever the reason, if you’re looking to brand your startup company with something that says New Hampshire and every option containing “Granite State” is already taken, those three little digits are still good.


(David Brooks can be reached at 369-3313 or

David Brooks bio photo

David Brooks is a reporter and the writer of the sci/tech column Granite Geek and blog, as well as moderator of Science Cafe Concord events. After obtaining a bachelor’s degree in mathematics he became a newspaperman, working in Virginia and Tennessee before spending 28 years at the Nashua Telegraph . He joined the Monitor in 2015.

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