Area Codes are used for routing long distance telephone calls to the appropriate local telephone exchanges. The system for assigning area codes and local exchange prefixes is managed by the North American Numbering Plan Administrator (NANPA) under the rules adopted by the Federal Communications Commission (FCC). As an area code nears the end of the supply of unassigned local prefixes, NANPA notifies the state regulatory commission and the telephone industry of the need for an area code relief plan. (See Frequently Asked Questions)
The adoption of the Telecommunications Act of 1996 introduced competition into the telephone industry and changed the approach to area code assignments. The FCC expressed a strong desire for a level playing field between existing local exchange telephone carriers, competing local telephone providers and wireless telephone service companies.
NANPA monitors the assignment and usage of telephone prefix codes and projects when area codes will need to provide some kind of additional capacity through area code relief. The FCC has provided that state regulators, such as the Iowa Utilities Board (IUB), may govern that relief process within FCC rules, or a state may decline and allow the FCC to do it. IUB members believe they are closer to the situation and have chosen to make the area code decisions for Iowa.
In April 1999, NANPA advised the IUB that projections indicated area code relief would soon be needed in 515, and a short time later in 319. That started the process that resulted in a relief plan being adopted for the 515 Area Code, and initiated the process for the 319 Area Code.
On November 8, 1999, the IUB petitioned the FCC for waiver on number conservation and 10-digit dialing. While it was recognized this might not be considered in time to help with 515, it could be useful in the 319 area code relief.