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Telecommunications

      
   
Area Code Relief - Background Information

Telephone Number Basics:

Our telephone numbering system operates under the North American Numbering Plan.  That plan, developed in 1947 by AT&T, and subsequently adopted by the Federal Communication Commission (FCC), established the 10-digit scheme we use today:

NPA
NXX
XXXX
 (e.g., the PSC’s number is 608-266-5481)
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Area Code CO Code Line Number  
  • The “NPA” (Numbering Plan Area) is the area code.  Wisconsin currently has 5 area codes: 715, 414, 608, 920, and 262.  An area code cannot begin with a 0 or a 1.

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  • The “NXX” is the central office (CO) code, also referred to as the “prefix.”  An NXX serves a specific exchange or rate center.  For a CO code, N = 2-9 and X = 0-9.

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  • The XXXX is the line number for a customer.  For these numbers, X = 0-9, thus, in any NXX code, there are potentially 10,000 line numbers available for assignment: 0000-9999.

Why are we running out of numbers?

In recent years, the prevalence of technology in everyday life has increased tremendously.   Many households no longer have a single phone number for the entire family.  Instead, customers often have multiple telephone lines, multiple cell phones and Internet access.  The combination of new technologies (i.e. OnStar, Voice over Internet Protocol), new telecommunications providers requiring their own telephone numbering inventories and the increased demand for telecommunications services in general (such as cellular phones, pagers, fax machines, modems, alarms and internet access) have strained our existing telephone number resources, both in Wisconsin and across the country.


Why do we need new area codes?

While many of the new technologies make life easier, they require the use of telephone numbers.  The rapid growth of the telecommunications industry has resulted in a relatively new phenomenon known as area code “exhaust.”  An area code reaches exhaust when nearly all of the telephone prefixes within that area code have been assigned.  It is now projected that the 715 area code will run out of new telephone prefixes by the third quarter of 2011 and that the 920 area code will run out of new prefixes by the fourth quarter of 2012.

In general, the North American Numbering Plan Administrator (NANPA) assigns telephone numbers to a telecommunications provider by NXX.  As more NXX codes in the area code are assigned, the area code approaches exhaust, thus creating the need for an additional area code to be added in that particular geographic area.  In recent years, regulators and the telecommunications industry have implemented various conservation measures to help reduce the rate of area code exhausts and to improve the utilization of the telephone numbers within a given NXX code.  These conservation measures include thousand-block number pooling, Local Number Portability which enables a customer to change service providers but keep their telephone number) and rate center consolidations where possible.