In the North American Numbering Plan, area code 925 is a California area code that covers the inland portions of the East Bay counties of Alameda and Contra Costa in Northern California.
It was originally part of the 415 area code, one of the first three area codes created in California in 1947, which originally covered all of central California. In 1991 the 510 area code was created to encompass most of the East Bay. The 925 area code was created March 14, 1998, when the 510 area code was itself split along the natural border of the East Bay Hills. The number was formed by taking 415 and adding 510 which equals 925.
The area code includes southeastern Alameda County, and all of Contra Costa County except the western part.
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In the North American Numbering Plan, area code 925 is a California area code that covers the...
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In the North American Numbering Plan, area code 925 is a California area code that covers the inland portions of the East Bay counties of Alameda and Contra Costa in Northern California.
It was originally part of the 415 area code, one of the first three area codes created in California in 1947, which originally covered all of central California. In 1991 the 510 area code was created to encompass most of the East Bay. The 925 area code was created March 14, 1998, when the 510 area code was itself split along the natural border of the East Bay Hills. The number was formed by taking 415 and adding 510 which equals 925.
The area code includes southeastern Alameda County, and all of Contra Costa County except the western part.
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