CALIFORNIA · AREA CODE GUIDE
820 area code location: Oxnard and Simi Valley, California
- Local date and time
- Pacific Time
Map data: HSIP (2010) · NANPA · US Census Bureau, checked 26 September 2026. Boundaries are approximate.
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Download the 820 area code map
A printable area code 820 location map, with time zone and state. Use the PNG image in a document or slide; the SVG stays sharp at any size.
820 area code at a glance
- State
- California
- Primary cities
- Oxnard, Simi Valley, and Thousand Oaks
- Established
- Population
- Largest community: Oxnard, 199,651 (2025)Not an area-code population.
- Prefixes in service
- 89 as of 13 October 2026
An area code does not show where a caller is now.
History
Country and calling code: United States (+1).
Parent code: 805.
New code planned: No, as of 22 September 2026.
Time zone
- Pacific Time
- Standard time UTC−08:00
- Daylight saving time UTC−07:00
Counties and cities covered
820 numbers are issued across 40 communities. These are telephone exchange areas, which follow the phone network rather than city limits, so a place can sit just outside the boundary of the town it is named for.
Counties of the communities we could place (the code may reach further): Ventura County, San Luis Obispo County, and Santa Barbara County.
- Oxnard
- Simi Valley
- Thousand Oaks
- Santa Maria
- Santa Barbara
- Camarillo
- San Luis Obispo
- Lompoc
- Moorpark
- Santa Paula
- Atascadero
- Arroyo Grande
- Fillmore
- Carpinteria
- Morro Bay
- Guadalupe
- Pismo Beach
- Ojai
- Bradley
- Cambria
- Carrisa Plains
- Cayucos
- Conejo
- El Rio
- Gaviota
15 more communities
- Los Alamos
- Newbury Park
- Nipomo
- Oak View
- Parkfield
- Paso Robles
- Piru
- Point Mugu
- San Miguel
- Santa Margarita
- Santa Ynez
- Saticoy
- Somis
- Ventura Central
- Ventura East
Notable places in 820
| Place | Where | What it is |
|---|---|---|
| University of California, Santa Barbara | 12.3 km from Santa Barbara | University, 27,662 12-month enrollment (2023–24) |
| Vandenberg Space Force Base | 10.3 km from Lompoc | US Air Force installation |
| California Polytechnic State University | 4.0 km from San Luis Obispo | University, 23,829 12-month enrollment (2023–24) |
| Ronald Reagan Presidential Library | 6.0 km from Moorpark | Museum |
| Santa Barbara Municipal Airport | 11.9 km from Santa Barbara | Commercial airport, 696,396 enplanements (2024) |
| California State University, Channel Islands | 6.7 km from Camarillo | University, 6,662 12-month enrollment (2023–24) |
| Santa Maria Public Airport | 4.0 km from Santa Maria | Commercial airport, 13,525 enplanements (2024) |
| Oxnard Airport | 0.2 km from Oxnard | Airport |
| Naval Air Station Point Mugu | 11.9 km from Oxnard | Military base |
| Mullin Automotive Museum | 4.4 km from Oxnard | Museum |
Also serving this area
Questions about 820
Where is the 820 area code?
820 is in California. Its numbers are issued in Oxnard, Simi Valley, Thousand Oaks, and 37 other communities.
What time zone is area code 820 in?
820 is in Pacific Time. Daylight saving time is observed.
Is 820 an overlay?
Yes. 820 was added as an overlay on 805 on 30 June 2018.
What cities are in the 820 area code?
Oxnard, Simi Valley, Thousand Oaks, Santa Maria, and Santa Barbara, and 35 other communities.
What state is area code 820 in?
Area code 820 is in California.
What counties are covered by area code 820?
Area code 820 covers communities in Ventura County, San Luis Obispo County, and Santa Barbara County.
Is 820 a toll-free area code?
No. 820 is a geographic area code. The toll-free codes are 800, 833, 844, 855, 866, 877, and 888.
Sources: NANPA area code listing, NANPA places by area code, NANPA central office code assignments, U.S. Census Bureau population estimates, OMB metropolitan area delineations. Checked .
Business phone numbers in area code 820, answered by an AI agent
A local number for Oxnard, Simi Valley, and Thousand Oaks, California, with an AI receptionist that takes caller details, answers the questions you give it, and books appointments. Numbers depend on what carriers have left.