Indiana Area Codes
Because of cellular phones, pagers, the Internet and other telecommunications services that have become popular in the last 15 years, consumers throughout the United States and Canada have needed additional phone numbers at an increasing rate. The shrinking of phone numbers available for distribution is called “number depletion.”
To create new telephone numbers to keep up with demand, new area codes have been introduced in 37 states, including Indiana, in the last decade. In fact, the number of area codes in the United States has more than doubled since 1995.
Number conservation efforts are helping Indiana make more efficient use of existing numbers and have delayed the need to implement many new area codes. The most significant effort is "1,000 block number pooling," which Indiana started using in 2001. Traditionally, telecommunications providers were allocated blocks of 10,000 numbers, which often left numbers unused. Now, numbers can be allocated in blocks of only 1,000.
A Brief History
When North America’s telephone numbering system went into effect in 1947, three area codes were assigned to Indiana: 219, 317 and 812. These codes remained largely unchanged for nearly 50 years, until number depletion became an issue.
The 765 area code was introduced in 1996, as a split from the 317 area that spanned the central third of Indiana. Communities outside the Indianapolis metropolitan area that had used 317 were assigned the new 765 area code. Indianapolis and most of its suburbs continue to use 317.
In 2002, the 219 area that had spanned northern Indiana for decades was divided into thirds, with the new 260 and 574 area codes being introduced. (More information on these changes, including lists of communities by area code, is available on the OUCC Website.)
Had 1,000 block number pooling not been implemented, other parts of Indiana would have required additional new area codes in recent years. While relief measures are delaying that need, each area code has a finite supply of available numbers – meaning that future changes are inevitable.
Maximizing Current Numbers
Among Indiana’s original three area codes, only 812 – spanning the state’s southern third – has not required major changes. However, the current industry forecast* projects that 812 will run out of numbers in 2011. Forecasts several years ago set 2004 as 812’s expected exhaust date, but number conservation efforts have extended the lifespan considerably.
1,000 block number pooling has extended the 765 area code’s projected exhaust date to 2014 – a ten-year extension beyond projections made a few years ago.
The 317 area code’s number supply is also currently projected to run out in 2013 – eleven years later than projections made before 1,000 block number pooling was implemented.
The three area codes serving northern Indiana (219, 574 and 260) are expected to need no additional changes before 2027.
Implementing new area codes
After efficiency efforts are exhausted, new area codes can be implemented either by geographic split or overlay.
In a geographic split, an existing area code zone is split into at least two parts. One part typically keeps the original area code while the other part(s) is assigned a new area code. A geographic split does not change the boundaries of a consumer’s free local calling area. Most local calls are still placed using seven-digit dialing.
In an overlay, a new area code "overlays" the entire geographic area covered by the existing area code. Existing phone numbers, fax machines, etc., retain current area codes and phone numbers, but new phones and telecommunications devices may be assigned numbers using the new area code. An overlay does not change the boundaries of a consumer’s free local calling area, but all calls - including free local calls - usually require 10-digit dialing.
Note
* Projections in this fact sheet are according to North American Numbering Plan Administration (NANPA) data released March 28, 2008. NANPA is the neutral, third party administrator that oversees area code assignments. For additional information on area code relief, as well as state maps of area codes in North America, visit NANPA’s Website at http://www.nanpa.com/.
Indiana Office of Utility Consumer Counselor
115 W. Washington St., Suite 1500 South
Indianapolis, IN 46204
http://www.openlines.in.gov/
uccinfo@oucc.IN.gov
toll-free: 1-888-441-2494
voice/TDD: 317-232-2494
fax: 317-232-5923
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