California · Pacific Time
820 Area Code
Area code 820 is in California, serving California Central Coast: Ventura, Santa Barbara and San Luis Obispo counties. It is in the Pacific Time zone. It shares its territory with overlay code 805, so 10-digit dialing is required.
Last updated October 1, 2026 · Source: NANPA
Where is the 820 area code?
820 is a California area code covering California Central Coast: Ventura, Santa Barbara and San Luis Obispo counties. In the wider directory it sits in the West region.
Cities in the 820 area code
- Oxnard
- Thousand Oaks
- Simi Valley
- Ventura
- Santa Maria
- Camarillo
- Santa Barbara
- San Luis Obispo
- Moorpark
- Lompoc
- Goleta
- Paso Robles
- Atascadero
Counties served by 820
Ventura County, Santa Barbara County and San Luis Obispo County.
820 overlay codes and dialing
The 820 territory is covered by an overlay of 2 area codes: 805, 820. All of them serve the same geographic area, and the original code is 805. Because more than one code covers the same ground, 10-digit dialing is mandatory — you must dial the area code for every local call. New phone lines may be assigned any of these codes.
History of the 820 area code
820 went into service on June 30, 2018 as an overlay of 805, relieving number exhaustion in the Oxnard area. Rather than splitting the region, the overlay lets existing customers keep their numbers while new lines draw from the added code. Learn more in our overlay guide.
Is 820 a scam or spam risk?
820 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 820 number on your screen is no guarantee the caller is in Oxnard, CA or trustworthy. See spam & scam-risk area codes for how spoofing works and how to respond.
Other California area codes
Explore more
See every code in California, compare codes across the West region, or view all Pacific Time codes. You can also browse the 8XX 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
820 area code FAQ
Where is the 820 area code?
The 820 area code is in California, covering California Central Coast: Ventura, Santa Barbara and San Luis Obispo counties, in the West region.
What cities are in the 820 area code?
Cities in the 820 area code include Oxnard, Thousand Oaks, Simi Valley, Ventura, Santa Maria, Camarillo, Santa Barbara, San Luis Obispo, Moorpark and Lompoc.
What time zone is 820 in?
820 is in the Pacific Time zone.
What is the overlay for the 820 area code?
820 shares its territory with 805. Both codes (805, 820) serve the same area, so 10-digit dialing is required for every call.
When did the 820 area code start?
820 went into service on June 30, 2018 as an overlay of 805.
Do I have to dial 10 digits for 820?
Yes. Because 820 is an overlay area, you must dial the full 10-digit number (area code + 7 digits) for every call.
Is 820 a toll-free or premium code?
No. 820 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.