Area code 520

Clickable map of Arizona area codes in blue (and border states) with Area Code 520 shown in red

Area code 520 is a telephone area code in the North American Numbering Plan (NANP) for the U.S. state of Arizona. The numbering plan area comprises Tucson and most of the southeastern part of the state.

Area code 520 was created in a split from area code 602 on March 19, 1995. Previously, 602 had been the sole area code for the entire state of Arizona since the introduction of area codes in 1947 until Arizona's rapid expansion during the second half of the 20th century, and the proliferation of mobile and data communication services in the 1990s required additional numbering resources.

History[]

Originally, 520 encompassed the entire state outside the Phoenix metropolitan area, as well as a few outer portions of western and southern Maricopa County. It completely surrounded 602, which was retained by most of the Phoenix area.

Within two years of its creation, however, 520 was already close to exhaustion due to the rapid growth of the Tucson area (and to a lesser extent Yuma and Flagstaff) as well as the proliferation of cell phones and pagers. In 2001, the northern and western portions of the old 520 split off as area code 928. All of Pima, Santa Cruz and Cochise counties, most of Pinal County and part of far southern Maricopa County kept 520, while Yuma and La Paz counties, far western Maricopa County and all of northern Arizona were switched to 928.

Prior to October 2021, area code 520 had telephone numbers assigned for the central office code 988. In 2020, 988 was designated nationwide as a dialing code for the National Suicide Prevention Lifeline, which created a conflict for exchanges that permit seven-digit dialing. This area code was therefore scheduled to transition to ten-digit dialing by October 24, 2021.^[1]

Service area[]

Counties[]

Municipalities[]

References[]

^ "Transition to 10-digit dialing (for 988 as 3-digit access to National Suicide Prevention Hotline)" (PDF). North American Numbering Plan Administrator. January 8, 2021. Retrieved March 9, 2021.

External links[]

NANPA area code map of Arizona

Arizona area codes: 480, 520, 602, 623, 928
	North: 480, 602, 928
West: 623, 928	area code 520	East: 575
	South: Country code +52 in Mexico
New Mexico area codes: 505, 575

Coordinates: 32°N 111°W / 32°N 111°W / 32; -111

[pl556-1] "Transition to 10-digit dialing (for 988 as 3-digit access to National Suicide Prevention Hotline)" (PDF). North American Numbering Plan Administrator. January 8, 2021. Retrieved March 9, 2021.

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