Area codes 208 and 986
Area codes 208 and 986 are the area codes in the North American Numbering Plan for all of Idaho. Area code 208 is one of the 86 original area codes created by AT&T in 1947. It was Idaho's sole area code until 2017, when 986 was added as an overlay plan for the entire state. Because of its small population, Idaho was among a declining number of North American jurisdictions with only one area code. It is also one of the few whole-state area codes split between multiple LATAs—Southern Idaho (centered in  Boise and spilling into Nevada, Wyoming and Malheur County, Oregon) and Coeur d'Alene (spilling into Montana and Washington). Additionally, the Spokane, Washington LATA spills into central Idaho. In 2001, the Federal Communications Commission projected that demand would exhaust the numbering pool of area code 208 in 2003. The number shortage was a result of the proliferation of landlines, cellphones, and pagers, particularly in urban areas, in the 1990s. However, in 2002 the Idaho Public Utilities Commission (IPUC) successfully delayed a split by implementing number pooling in Boise; this was later applied in 2007 to the rest of Idaho to stave  off projected exhaustion in 2010. In the summer of 2013, NANPA projections suggested exhaustion in 2018. By this time all conservation measures had been exhausted. With Idaho's population growing closer to two million, a second area code became necessary; eleven other states with single area codes all have populations of about one million each. Ultimately, a statewide overlay was recommended. This would have had the effect of assigning 15.6 million numbers to a state of just over 1.7 million people. However, the Idaho PUC wanted to spare Idahoans, particularly in rural areas, the expense and burden of having to  change their numbers. An area code split would have also required "en masse" reprogramming of cell phones. In the overlay plan, subscribers with numbers in the original area code can keep it. On November 2, 2015, the Idaho PUC approved the addition of area code 986 as a statewide overlay. 986 officially entered service on November 5, 2016. On that date, a permissive dialing period began during which it was possible to make calls with either seven or ten digits (the latter with the area code first). Ten-digit dialing became mandatory across Idaho on August 5, 2017; failure to  dial the area code caused an intercept message as reminder. 986 is the second statewide overlay, following the example of area codes 304 and 681 in West Virginia.