Area code 520
area codes in the United States
Area code 520 is a telephone area code in the North American Numbering Plan. It covers southern Arizona, including cities like Tucson, Sierra Vista, and Nogales. Area code 520 entered service on March 19, 1995 as a split from 602 and surrounded the Phoenix metropolitan area. It was the third interchangeable area code to be introduced after 334 and 360. It was split by 928 in 2001 and limited to the southern section of Arizona.