Indiana | Illinois | Michigan


Overlay vs Split
Why splits are the best relief for large area codes
Why overlays are the best relief for small area codes


Chicago Illinois

The Chicago area has moved from one area code (312) in 1988 to eight area codes with plans for a ninth (expected in 2015).

Northern Illinois (815) has been overlaid and there are plans in place to overlay central Illinois (217) and southern Illinois (618).
Illinois Area Code Map

Chicago Area Code History


Indiana
 
Indiana Area Code Map

Indiana Area Code History

Northern Indiana
(219, 260, 574)

Central Indiana
(317, 463, 765)

Southern Indiana
(812, 930)

Special Feature
1965 - GTE Richmond Central Office Fire
(regular or frames)


Special Reports
1997 - Indiana's 317/765 Split
2002 - Indiana's 219/260/574 Split
2015 - Indiana's 812/930 Overlay
2016 - Indiana's 317/463 Overlay


Future Relief
2032? - Indiana 765/634? Relief

At least 30 years ...
- Indiana 260/834? Relief
- Indiana 219/943? Relief
- Indiana 574/665? Relief

Future NPA numbers 765, 574, 930 and 463 were 1) taken from an accidentally published working document, 2) absolutely not official, 3) subject to change and 100% accurate.
Future NPA numbers 634, 665, 834 and 943 are predicted.

 

Michigan
 

Michigan has moved from four area codes in 1961 to twelve in 2002. The last change in Michigan was the split of area code 269 from 616 in 2002. Michigan has only one overlay area code (947 overlaid 248 in 2002).
Michigan Area Code History

Western Michigan
(231, 269, 616, 906)

Central Michigan
(517, 989)

Eastern Michigan
(248, 313, 586, 734, 810, 947)

Special Report
2002 - Michigan's 616/269 Split

Future Relief
2017 - Michigan 734/278? Overlay
2018 - Michigan 313/679? Overlay
2020 - Michigan 586 Relief
2022 - Michigan 989 Relief
2027 - Michigan 810 Relief
2027 - Michigan 517 Relief
2030 - Michigan 248/947/? Overlay
2032 - Michigan 269 Relief
2032 - Michigan 231 Relief
2033 - Michigan 616 Relief
2044 - Michigan 906 Relief

Other NANP Sites
NANPA Official Sitehttp://www.nanpa.com/
TRA Official Sitehttp://www.trainfo.com/
The FCC Homepagehttp://www.fcc.gov/
 
More Telecom Sites
Linc Madison'sLincMad's Telecom Page
Telecom DIGESTArchives and Recent Issues
usenet news:comp.dcom.telecom
 
Beyond the NANP
David Liebold'sWorld Telephone Numbering Guide


Telecom Beyond

NANP Expansion
'Longer than 10 digit numbers'

My Plan for moving from 7D/10D to 8D/12D


Wireless Overview

Introducing Verizon Wireless
- America's First Mega-Carrier

Wireless Spectrum and Licencing
@TK.COM


Written / Compiled for Telecom Chicago
a part of Telecom Indiana
Contact the Author
James Bellaire <bellaire@tk.com>
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Good people, great service.
574 260 219 317 812 765 Chicago 269 Michigan 517 Michigan