408 Area Code: San Jose, CA | Location & Time Zone

The 408 area code serves San Jose, California, and the surrounding Silicon Valley region. Established in 1959, this area code covers one of the most technologically advanced regions in the United States, including major cities like San Jose, Santa Clara, Sunnyvale, and Cupertino. Whether you’re looking to understand the geographic coverage, time zone information, or dialing procedures for the 408 area code, this comprehensive guide provides all the essential details you need.

What is the 408 Area Code?

The 408 area code is a geographic telephone area code that primarily serves San Jose, California, and the broader Santa Clara County region. This area code was established on April 1, 1959, as a split from the original 415 area code that previously covered the entire San Francisco Bay Area. The 408 region encompasses the heart of Silicon Valley, home to countless technology companies, startups, and innovation centers that have shaped the modern digital landscape.

Originally covering a much larger geographic area, the 408 area code has undergone several changes over the decades. The region experienced rapid population and business growth, particularly during the technology boom, which necessitated the introduction of overlay area codes to meet the increasing demand for phone numbers. Today, the 408 area code works alongside the 669 overlay area code, which was introduced in 2012 to serve the same geographic region.

408 Area Code Location & Coverage

Cities and Regions Covered

The 408 area code covers Santa Clara County and serves numerous cities throughout the Silicon Valley region. Major cities within the 408 area code include San Jose (the largest city in the coverage area and the third-largest city in California), Santa Clara, Sunnyvale, Mountain View, Cupertino, Milpitas, Campbell, Los Gatos, Saratoga, and Morgan Hill. The area code also serves smaller communities such as Los Altos, Los Altos Hills, Monte Sereno, and portions of Fremont.

This region is globally recognized as the epicenter of the technology industry, housing headquarters for major corporations including Apple, Google, Facebook (Meta), Netflix, Adobe, and countless other tech giants. The area also includes Stanford University, which has played a crucial role in the development of Silicon Valley’s innovation ecosystem. The 408 area code region extends from the San Francisco Bay in the north to the Santa Cruz Mountains in the west and south.

Geographic Coverage Map

The 408 area code coverage area spans approximately 1,300 square miles within Santa Clara County. The region is bounded by the San Francisco Bay to the north and northeast, the Santa Cruz Mountains to the west and southwest, and extends south toward Gilroy and the Monterey County border. The eastern boundary includes the Diablo Range foothills. This strategic location provides the area with diverse geography, from bay shores and flatlands ideal for urban development to mountainous regions offering recreational opportunities.

Time Zone Information

The entire 408 area code region operates on Pacific Time, which is three hours behind Eastern Time and eight hours behind Coordinated Universal Time (UTC) during standard time. Like most of California, the region observes Daylight Saving Time, moving clocks forward one hour in March and back one hour in November. This time zone alignment is crucial for business operations, as many companies in the 408 area code conduct business with partners and clients across different time zones, particularly on the East Coast and internationally. For current local time and Current Local Times Around the World, users can access real-time information.

408 Area Code Details

The 408 area code is classified as a geographic area code, meaning it serves a specific geographic region rather than being assigned to particular services or mobile carriers. The North American Numbering Plan Administration (NANPA) oversees the allocation and management of this area code. As demand for phone numbers increased due to population growth and the proliferation of mobile devices, the 669 overlay was implemented to serve the same geographic area, requiring 10-digit dialing for all calls within the region.

History of 408 Area Code

When Was 408 Created?

The 408 area code was established on April 1, 1959, as part of a comprehensive reorganization of California’s telephone numbering system. Prior to this date, the entire San Francisco Bay Area, including what is now the 408 region, was served by the 415 area code. The creation of 408 was necessary due to rapid population growth and increased demand for telephone services in the post-World War II era. The split assigned 408 to the southern and eastern portions of the Bay Area, including San Jose and surrounding communities.

The timing of the 408 area code creation coincided with significant economic and demographic changes in the region. The 1950s marked the beginning of what would later become known as Silicon Valley, with the establishment of technology companies and research facilities. This early infrastructure development laid the groundwork for the region’s eventual transformation into the global center of technology innovation.

Area Code Changes and Overlays

The most significant change to the 408 area code occurred in 2012 with the implementation of the 669 overlay area code. This overlay was introduced to address the depletion of available phone numbers within the 408 area code, a result of continued population growth, business expansion, and the widespread adoption of mobile phones, fax machines, and internet services requiring dedicated phone lines. The 669 overlay serves the exact same geographic area as 408, meaning both area codes can be assigned to numbers within Santa Clara County.

The introduction of the 669 overlay required significant changes to dialing procedures. Beginning November 20, 2012, all calls within the region required 10-digit dialing (area code + seven-digit number), even for local calls. This change affected both residential and business customers, requiring updates to phone systems, address books, and automated dialing equipment. The overlay system allows for more efficient use of available number combinations while preserving the established 408 area code that many businesses and residents preferred to keep.

How to Call 408 Area Code

Dialing Within the Area Code

When making calls within the 408 area code region, callers must use 10-digit dialing due to the 669 overlay implementation. This means you must dial the area code (either 408 or 669) followed by the seven-digit phone number, even for local calls. The format is: 408-XXX-XXXX or 669-XXX-XXXX. This requirement applies to all calls, whether you’re calling from a landline or mobile phone, and regardless of whether you’re calling a number with the same area code as your own.

For those using timing applications or need precise coordination, Timer Tools can be helpful for managing call scheduling across different time zones. The 10-digit dialing requirement ensures that calls are properly routed to the correct destination, as the same seven-digit number can exist in both the 408 and 669 area codes within the same geographic region.

Dialing From Other Area Codes

When calling a 408 area code number from outside the local region, you must dial 1 followed by the complete 10-digit number. The format is: 1-408-XXX-XXXX. This applies to all long-distance calls within the United States and Canada. The “1” prefix indicates that you’re making a long-distance call within the North American Numbering Plan, which includes the United States, Canada, and several Caribbean nations.

Most modern phone systems automatically recognize when a long-distance prefix is required, but it’s important to include the “1” to ensure proper call routing and billing. Some phone carriers and VoIP services may not require the “1” prefix for certain types of calls, but including it ensures compatibility across all systems and carriers.

International Dialing

For international callers attempting to reach a 408 area code number, the format is: +1-408-XXX-XXXX. The “+1” represents the country code for the United States and Canada within the international dialing system. Depending on the originating country, callers may need to dial a specific international access code (such as 00, 011, or others) before the country code and phone number.

International calling procedures can vary significantly between countries and carriers, so callers should verify the correct dialing format with their local telephone service provider. Many modern smartphones automatically format international numbers correctly when using the “+” symbol, which simplifies the process for mobile users traveling internationally or making international calls.

Nearby Area Codes

The 408 area code is strategically located within the San Francisco Bay Area, surrounded by several other area codes that serve neighboring regions. The proximity to these area codes reflects the interconnected nature of the Bay Area economy and transportation networks. The 650 area code, serving San Mateo County and parts of Santa Clara County, is the closest neighboring area code and often causes confusion due to overlapping coverage areas in some locations.

Understanding nearby area codes is particularly important for businesses operating in the 408 region, as many companies have operations, suppliers, or customers in adjacent areas. The close proximity of these area codes also affects telecommunications infrastructure and call routing, as many calls between these regions are considered local or regional rather than long-distance calls.

Population & Demographics

The 408 area code region serves approximately 1.95 million residents within Santa Clara County, making it one of the most densely populated area codes in California. San Jose, the largest city in the region, has a population of over one million people, making it the third-largest city in California and the tenth-largest city in the United States. The region has experienced consistent population growth over the past several decades, driven primarily by economic opportunities in the technology sector.

The demographic composition of the 408 area code region is notably diverse, with significant Asian American, Hispanic, and White populations. The area has a highly educated workforce, with a large percentage of residents holding bachelor’s or advanced degrees, reflecting the knowledge-based economy that dominates the region. The median household income in the 408 area code region is significantly higher than the national average, though this is offset by a substantially higher cost of living, particularly housing costs.

The economic profile of the 408 area code region is dominated by technology companies, ranging from established multinational corporations to innovative startups. Major employers include Apple, Google, Adobe, Netflix, eBay, and numerous other technology firms. The region also has a significant presence in biotechnology, clean energy, and aerospace industries. This economic diversity has made the area resilient to economic fluctuations, though it remains sensitive to changes in the technology sector.

Frequently Asked Questions

What cities are in the 408 area code?

The 408 area code serves San Jose, Santa Clara, Sunnyvale, Mountain View, Cupertino, Milpitas, Campbell, Los Gatos, Saratoga, Morgan Hill, Los Altos, Los Altos Hills, Monte Sereno, and portions of other communities within Santa Clara County, California.

Do I need to dial 10 digits for local calls in the 408 area code?

Yes, 10-digit dialing is required for all calls within the 408 area code region, including local calls. This requirement was implemented in 2012 when the 669 overlay area code was introduced to serve the same geographic area.

What time zone is the 408 area code in?

The 408 area code is in the Pacific Time Zone (PST/PDT), which is UTC-8 during standard time and UTC-7 during daylight saving time. The region observes daylight saving time from March to November.

When was the 408 area code created?

The 408 area code was established on April 1, 1959, as a split from the original 415 area code that previously served the entire San Francisco Bay Area. It was created to accommodate growing demand for telephone services in the South Bay region.

What is the overlay area code for 408?

The 669 area code serves as an overlay for the 408 area code region. Implemented in 2012, the 669 overlay covers the exact same geographic area as 408, serving Santa Clara County and surrounding communities.

Is 408 a toll-free area code?

No, 408 is not a toll-free area code. It is a geographic area code serving specific locations in California. Toll-free area codes include 800, 833, 844, 855, 866, 877, and 888.

Conclusion

The 408 area code represents one of the most economically significant and technologically advanced regions in the United States. Serving San Jose and the broader Silicon Valley area, this area code connects millions of residents, businesses, and organizations within Santa Clara County. Understanding the 408 area code’s coverage, time zone, dialing procedures, and history is essential for anyone conducting business or maintaining personal connections in this vital region. For additional resources on time management and zone calculations, visit Blog Guides Section for comprehensive telecommunications and timing information.

Whether you’re a business looking to establish operations in Silicon Valley, a resident navigating the local telecommunications landscape, or someone simply trying to understand how to properly dial numbers in the 408 area code region, this guide provides the foundation for successful communication within one of California’s most dynamic and influential areas. The 408 area code will continue to serve this growing region alongside its 669 overlay, supporting the ongoing technological innovation and economic development that defines Silicon Valley.