Area code 408 covers the southern region of the San Francisco Bay area. This area code includes Santa Clara county and parts of Stanislaus, Alameda and northern Santa Cruz counties.
Businesses and individuals in the San Jose Metropolitan Statistical Area are the predominant users of the 408 area code. Other metropolitan areas covered by area code 408 include Campbell, Santa Clara, Milpitas, Gilroy and Sunnyvale, California.
The number 408 first became an area code in June 1959 due to a split of the 415 area code. In 1999, the 408 area code split, removing San Benito County and most of Monterey County and Santa Cruz County from the service area.
Area code 669 became effective Nov.12, 2012, as an overlay of the 408 area code. Therefore, all telephone users in the 408 and 669 area codes must include the area code whenever dialing a telephone number within their area.