Area Code 602 is an Area Code in Arizona in the Southwestern United States that used to cover the entire state of Arizona, but due to huge population gains in the state, mainly greater Phoenix, in the 1990s and 2000s, it started to get split. The first split came on March 19th, 1995; Greater Phoenix kept Area Code 602, and the rest of the state became Area Code 520. The next split came on April 1st, 1999; when it was deemed that Greater Phoenix needed multiple area codes. The western suburbs and the city west of 39th Ave North of Indian School to west of 63rd Ave from I-10 south became Area code 623, along with the city from North of Union Hills and west of the 2000 E Grid. On the east side everything from about 56th Street eastward including the East Valley Suburbs, and the Town of Paradise Valley (which goes as far west as 32nd St) became Area Code 480; as well as the city North of Union Hills and east of the 2000 E Grid. This was the last change made to the 602 area code to date. Area Code 520 is a telephone dialing code within the State of Arizona in the southwestern united States. ... This page meets Wikipedias criteria for speedy deletion. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...