Area code 669 is an overlay for area code 408, serving much of Silicon Valley, including San Jose, Cupertino, and Sunnyvale. Introduced in 2012, it helps accommodate the booming tech-driven population growth in this global innovation hub. The region includes headquarters for Apple, Cisco, and other major firms. Ten-digit dialing is required. 669 may be modern, but it’s closely linked to the digital economy and technological advancement of the Bay Area.