Area Code 408
California
Area code 408 serves California, primarily San Jose, in the Pacific Time (PT) time zone. It has served the region since 01-Jan-1959.
Overlay Area Code
This area code is part of an overlay region, meaning the same geographic area is served by multiple area codes. Overlay codes were introduced to meet growing demand for phone numbers without requiring existing customers to change their numbers.
This area code shares its geographic region with: area code 669 (San Jose).
In service since: 01-Jan-1959
Area Code Splits
Parts of this area code’s original geographic region were later assigned new area codes through splits. When a split occurs, some customers in the original area code region are assigned the new area code.
Split into: area code 831 (Salinas).
Demographics & Economics
- Total Population
- 1,705,544
- Population Density
- 1,462 people/sq miabove U.S. average (U.S.: 93 people/sq mi)
- Median Household Income
- $159,674above U.S. median (U.S.: $75,144)
- Poverty Rate
- 6.9%below U.S. average (U.S.: 11.5%)
- Unemployment Rate
- 4.5%above U.S. average (U.S.: 3.6%)
- Education Attainment
- Bachelor's Degree+55.8%above U.S. average (U.S.: 33.7%)High School or Lower19.9%
Statistics are population-weighted aggregations from Census ACS 5-year estimates. Population figures are approximate — see Sources & Methodology for details on how area code populations are derived.
See how this area code compares to all US area codes in the Statistics dashboard.
Time Zone
- Pacific Time (PT)
NANPA Relief Status
According to the latest NANPA analysis (July 2026), this area code is not currently listed as exhausting within the next 36 months. No relief planning is in progress for this NPA.
Source: NANPA NPA Relief Planning Reports · See all relief planning statuses
Current Time
Prefix Utilization
Geographic Coverage
State
CA
Major Cities
- San Jose
- Sunnyvale
- Santa Clara
- Burbank
- Milpitas
- Cupertino
- Gilroy
- Morgan Hill
- Campbell
- Los Gatos
- Saratoga
- Alum Rock
- East Foothills
- San Martin
- Cambrian Park
- Monte Sereno
- Lexington Hills
- Fruitdale
Historical Timeline of Area Code 408
On March 1, 1959, area code 408 was carved out of area code 415 to serve the rapidly expanding San Jose and South Bay region of California. The code's trajectory mirrors the rise of Silicon Valley from agricultural orchards to the world's technology capital. Source: CPUC
Key milestones:
- 1947: The region was included in area code 415, one of California's original three area codes established under the North American Numbering Plan
- 1959: Area code 408 was created on March 1 by splitting from 415 to accommodate growth in the San Jose metropolitan area (Source: Wikipedia)
- 1998: Area code 831 was split off for Santa Cruz, Salinas, Monterey, and Hollister regions
- 1998: The California Public Utilities Commission approved an overlay for the 408 region under Decision D.98-11-065
- 1999: The overlay was suspended under Decision D.99-12-051 after number conservation measures reduced the immediate need for additional assignments
- 2001: Thousand-block number pooling was implemented, extending prefix availability by over a decade
- 2011: The CPUC re-approved the overlay under Decision D.11-10-031, citing NRUF data showing imminent exhaustion
- 2012: Area code 669 was activated on November 20, becoming the first overlay in the San Francisco Bay Area
The 14-year gap between the initial overlay approval in 1998 and its activation in 2012 demonstrates the effectiveness of number conservation strategies. Thousand-block pooling, implemented in 2001, delayed exhaustion by over a decade and became a model for resource management across the numbering plan. Source: CPUC Press Release
Regulatory History
Area code 408 has been managed through California Public Utilities Commission proceedings since 1959. The regulatory record shows how number conservation measures extended the life of the original assignment by more than a decade before an overlay became necessary. Source: CPUC
| Year | Event | Docket | Regulatory Action & Impact |
|---|---|---|---|
| 1959 | Area code creation | NANPA | 408 split from area code 415 to serve the San Jose and South Bay region (Source: Wikipedia) |
| 1998 | Area code split | CPUC | Area code 831 created to serve the coastal communities of Santa Cruz, Salinas, Monterey, and Hollister |
| 1998 | Overlay approval | D.98-11-065 | CPUC approved an overlay for the 408 region to address number exhaustion (Source: CPUC) |
| 1999 | Overlay suspension | D.99-12-051 | CPUC suspended the overlay after number conservation measures, including thousand-block number pooling, reduced immediate need for additional numbers |
| 2001 | Number pooling | CPUC | Thousand-block number pooling implemented in the 408 area, extending prefix availability by over a decade (Source: CPUC) |
| 2011 | Overlay re-approval | D.11-10-031 | CPUC re-approved the overlay citing NRUF data showing imminent exhaustion (Source: CPUC Decision D11-10-031) |
| 2012 | Overlay activation | CPUC | Area code 669 went into service on November 20, marking the Bay Area's first overlay (Source: CPUC Press Release) |
County Coverage
Population-weighted county share based on aggregated ZCTA population (100% = total mapped population for area code 408).
| County | Population | Share |
|---|---|---|
| Santa Clara, CA | 1,695,660 | 99.4% |
| Santa Cruz, CA | 9,884 | 0.6% |
Area Code 408 Family Tree
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Area code 408 was originally assigned in 01-Jan-1959 to serve CA. Over the years, it has generated 2 descendant area codes through a combination of geographic splits and overlays as demand for telephone numbers grew.
Call Context
This area code serves a major metropolitan region with high population density in CA. The primary city is San Jose.
Nearby Area Codes
Area codes geographically closest to 408.
Other Area Codes in California
Area codes that also serve California, linked for easy comparison.