Area Code 408: Locations, Carriers, and Regulations Explained

Area code 408 serves the southern San Francisco Bay Area, including parts of Santa Clara and Northern Santa Cruz counties in California.

What is Area Code 408?

Area code 408 is a crucial component of California's telecommunications network, primarily serving the southern San Francisco Bay Area. Established on March 1, 1959, it includes major cities like San Jose and Santa Clara.

Key Details

NPA Code: 408
Type: Overlay
Implementation Date: 1959
State: California

Geographic Coverage of Area Code 408

Area code 408 encompasses a significant portion of Santa Clara County and extends into parts of Northern Santa Cruz County.

Major Cities in Area Code 408

City	Latitude	Longitude
Campbell	37.28717	-121.94996
Gilroy	37.00578	-121.56828
Los Gatos	37.22661	-121.97468
Milpitas	37.42827	-121.90662
Morgan Hill	37.1305	-121.65439
San Jose	37.33939	-121.89496
Santa Clara	37.35411	-121.95524
Saratoga	37.26383	-122.02301
Sunnyvale	37.36883	-122.03635

Numbering and Utilization

Area code 408 has approximately 7.92 million numbers available, with a utilization rate of 70%. Projections suggest exhaustion by 2025.

Telecommunications Infrastructure

Major Carriers

AT&T: 40% market share
Verizon: 30% market share
T-Mobile: 20% market share
Others: 10% market share

Types of Services

Landline
Wireless
VoIP

Regulatory Overview

Area code 408 is regulated by the California Public Utilities Commission (CPUC). Compliance with the North American Numbering Plan Administration (NANPA) guidelines is mandatory.

Dialing Requirements

10-digit dialing has been mandatory since October 20, 2012.

Historical Milestones

1959: Area code 408 was created from area code 415.
1998: Geographic split led to the creation of area code 831.
2012: An overlay with area code 669 was implemented.

Conclusion

Area code 408 is vital for telecommunications in California's Bay Area, evolving through splits and overlays to meet increasing demand. It supports diverse services across various carriers.

For more detailed information, visit the North American Numbering Plan Administration website.