Area codes 805 and 820 are telephonearea codes in theNorth American Numbering Plan (NANP) for theU.S. state ofCalifornia. The numbering plan area (NPA) includes most or all of the counties ofSan Luis Obispo,Santa Barbara,Ventura, and the southernmost portions ofMonterey County. 805 was split fromarea code 213 in 1957, and area code 820 was added to the NPA in 2018, creating anarea code overlay.
Area code 805 was created in 1957, when one of theoriginal North American area codes in California, 213, was reduced in size to provide more central office codes in the Los Angeles area.
In 1998, the California-Nevada Code Administration (CNCA) determined that California was under "substantial number growth" which required exhaustion mitigation in the 805 numbering plan area,[1] by splitting the eastern part of the NPA into a new plan area with thearea code 661. The split was effective on February 13, 1999, for theSan Joaquin Valley,Santa Clarita Valley, andAntelope Valley.
In August 2016, theCalifornia Public Utilities Commission held a series of hearings for the decision of providing a relief area code in NPA 805 in the form of anoverlay or anarea code split.[2] On May 25, 2017, the Commission approved 820 as an overlay area code.[3][4] New telephone numbers of 820 area code began service in June 2018, requiringten-digit dialing for all calls.[5]
In addition to the municipalities below, area code 805 also serves the US military facilities inKwajalein,Republic of the Marshall Islands with aPaso Roblesprefix (805-355). This arrangement originated from theUS Army's first satellite communications station having been built at nearbyCamp Roberts.
| North:661,831 | ||
| West:Pacific Ocean,808 | area code 805/820 | East:559,661,818/747 |
| South:310/424, Pacific Ocean | ||
| Hawaii area codes:808 | ||