Arizona · Mountain Time
520 Area Code
Area code 520 is in Arizona, serving southern Arizona including Tucson, Casa Grande, Sierra Vista and Nogales. It is in the Mountain Time zone.
Last updated October 1, 2026 · Source: NANPA
Where is the 520 area code?
520 is a Arizona area code covering southern Arizona including Tucson, Casa Grande, Sierra Vista and Nogales. In the wider directory it sits in the West region.
Cities in the 520 area code
- Tucson
- Casa Grande
- Marana
- Oro Valley
- Sierra Vista
- Maricopa
- Sahuarita
- Douglas
- Nogales
- Eloy
- Coolidge
- Benson
Counties served by 520
Pima County, Pinal County, Cochise County and Santa Cruz County.
Time zone note: Arizona does not observe daylight saving time (except the Navajo Nation).
Dialing 520
Tucson, AZ is currently served by the single area code 520, with no overlay. Ten-digit dialing (area code + seven-digit number) always works and is increasingly the norm nationwide; some local calls may still connect with seven digits. If a future overlay is added, 10-digit dialing would become mandatory.
From outside the US, dial +1 520 followed by the seven-digit number.
History of the 520 area code
520 went into service on March 19, 1995, created when it was split from 602. It serves Tucson and the surrounding part of Arizona. For how codes are created, split, and overlaid, see how area codes work.
Is 520 a scam or spam risk?
520 is a legitimate geographic area code, not a premium or toll line, so a call from it costs you nothing extra. That said, scammers frequently spoof real local area codes to look familiar on caller ID. A genuine 520 number on your screen is no guarantee the caller is in Tucson, AZ or trustworthy. See spam & scam-risk area codes for how spoofing works and how to respond.
Explore more
See every code in Arizona, compare codes across the West region, or view all Mountain Time codes. You can also browse the 5XX block or the complete numeric list of US area codes.
New to how this all works? Start with how area codes work, then read up on overlays, 10-digit dialing, and spam & scam-risk codes. To check another number, use the area code lookup tool.
Quick answers
520 area code FAQ
Where is the 520 area code?
The 520 area code is in Arizona, covering southern Arizona including Tucson, Casa Grande, Sierra Vista and Nogales, in the West region.
What cities are in the 520 area code?
Cities in the 520 area code include Tucson, Casa Grande, Marana, Oro Valley, Sierra Vista, Maricopa, Sahuarita, Douglas, Nogales and Eloy.
What time zone is 520 in?
520 is in the Mountain Time zone. Arizona does not observe daylight saving time (except the Navajo Nation).
When did the 520 area code start?
520 went into service on March 19, 1995.
Do I have to dial 10 digits for 520?
Ten-digit dialing always works, and many areas now require it; some local calls in this area may still connect with seven digits.
Is 520 a toll-free or premium code?
No. 520 is a standard geographic area code, so calling it costs the same as any local or long-distance call on your plan. Toll-free calls use 800, 888, 877, 866, 855, 844 or 833.