408 Area Code: San Jose, 669 Overlay & History

The essentials

408 area code: quick facts

How 408 became San Jose's code

The CPUC says that in 1947, when area codes came to California, the area now served by 408 was part of 415, one of the first three area codes in the state. The CPUC's 2013 decision on 415 says 415 then covered the entire north coastal area of California, and that 707 and 408 were split from it in 1959. The timeline below uses the CPUC and the FCC.

1. 1959: Area code 408 is created by splitting 415. The FCC lists the opening as January 1959. The CPUC's 2011 decision says June 1959, so the two official sources give different months. See the note under the figure.
2. 1997: Because of high demand, NANPA, the numbering administrator, completes a relief planning process for 408 and starts rationing prefixes to carriers, according to the CPUC.
3. May 1998: The 408 area code is declared to be in jeopardy, meaning demand for prefixes could outrun supply before relief arrives. Rationing of two prefixes per month for carriers that are not pooling numbers continues from that point.
4. July 1998: The FCC lists 831 as opening in July 1998. The CPUC describes the split as taking place in 1999, when San Benito County and most of Monterey and Santa Cruz Counties were assigned 831.
5. November 19, 1998: The CPUC approves an overlay for 408 in Decision 98-11-065.
6. December 16, 1999: The CPUC indefinitely suspends that overlay plan in Decision 99-12-051.
7. 2001: Thousand-block number pooling takes effect in 408. The CPUC says this delayed exhaust for about a decade.
8. December 2, 2010: The industry reaches consensus to recommend an overlay. Public meetings follow on March 15 to 18, 2011, in San Jose, Los Gatos, and Morgan Hill.
9. June 1, 2011: NANPA, for the California telecommunications industry, files Application 11-06-008 asking the CPUC for 408 relief.
10. October 20, 2011: The CPUC adopts the 669 all-services overlay in Decision 11-10-031, issued October 21, 2011.
11. October 20, 2012: Dialing 1 plus the area code plus the number becomes mandatory for calls from 408.
12. November 20, 2012: The overlay takes effect and new services may be assigned 669 numbers. The FCC lists 669 as opening in November 2012.

Where area code 408 is used

The CPUC says 408 and its overlay code 669 serve primarily Santa Clara County, as well as neighboring cities and small unincorporated portions of Alameda and Santa Cruz Counties. The cities it names are San Jose, Campbell, Cupertino, Gilroy, Los Gatos, Milpitas, Monte Sereno, Morgan Hill, Santa Clara, Saratoga, Sunnyvale, and a portion of Palo Alto.

The CPUC's 2011 decision calls San Jose the state's third largest city, citing a 2010 California Department of Finance report. It describes the area as a mix of urban, suburban, rural and agricultural communities, and commercial and industrial areas, with an international airport, over a dozen colleges and universities, and about two dozen hospitals.

The same decision says the 408 area code has 11 rate centers. When it described a possible split, it named them: San Jose:North Da, San Jose:South Da, San Antonio, Morgan Hill, San Martin, and Gilroy in one half, and Sunnyvale, San Jose:West Da, Campbell, Saratoga, and Los Gatos in the other. A rate center is a billing area, not a boundary, and the list dates from 2011. The sources checked do not give street-level boundaries, so confirm a specific address with your phone provider.

Because 669 now covers the same ground, a 408 number no longer tells you which part of the territory it came from. See the section on the 669 overlay below.

Why 408 needed relief

An area code has a limited supply of prefixes, the three digits after the area code. The CPUC explains that a prefix cannot begin with 0 or 1, and that codes such as 211, 411, and 911 are set aside, which leaves 784 usable prefixes in an area code. Each prefix holds 10,000 line numbers. As of November 4, 2010, only 47 prefixes were left in 408.

The 2011 decision also explains who decides. The FCC holds responsibility for numbering but has delegated area code relief to the states, and in California the CPUC oversees it. NANPA forecasts each area code twice a year and normally starts relief planning about three years before a forecast exhaust. The industry then agrees on a plan, CPUC staff hold public meetings, and NANPA files an application for the CPUC to decide.

The CPUC says that thousand-block number pooling, in force since 2001, and other conservation measures extended the life of 408 by over ten years. By 2011 it said those measures had run their course. NANPA's October 2010 analysis forecast exhaust in the fourth quarter of 2012, and its April 2011 analysis moved that to the first quarter of 2013. A May 2012 CPUC release refers to the January 2013 forecasted exhaust.

The industry offered two options. An overlay would add a new code to the same area, with a projected life of 36 years. A split would divide 408 in two, with projected lives of 39 and 32 years, and everyone in the new half would have had to change area code. The CPUC chose the overlay. It said the overlay was less confusing for existing customers, was preferred by the industry and most of those who commented, and, according to a letter from the City of San Jose, would have the least impact on city services, in particular its emergency services.

NANPA's April 2026 analysis moved the 408/669 forecast out by four quarters and gives reduced historical and projected demand as the reason. Forecasts move from one analysis to the next, so treat the date as an estimate.

Area codes related to 408

The table shows the codes that the CPUC and FCC sources in this guide connect to 408. The sources checked do not describe every code that borders 408, so the table does not claim to show every neighbor.

The 669 overlay and what it changed

The CPUC describes an all-services overlay as a plan in which the original and new area codes apply to the same geographic area. For 408 that meant 669 was added on top of the existing territory, rather than carving out a new area.

• Existing numbers: the CPUC said no customers would have to change their area code or phone number.
• Prices and coverage: the CPUC said the overlay would only change dialing patterns, not the cost of a call, the coverage area, or other rates and services. A local call remains a local call regardless of the number of digits dialed.
• Schedule: the decision adopted a 13-month plan: six months of customer education and network preparation, six months in which calls within 408 could be dialed with 7 or 1+10 digits, then mandatory dialing, and the first 669 prefixes one month later.
• Public input: 137 people attended the March 2011 meetings and 49 spoke, 26 for an overlay and 13 for a split. By July 13, 2011, 204 of 247 online responses favored an overlay.

The 2011 overlay was not the first one approved for 408. The CPUC had approved an overlay in November 1998 and suspended it in December 1999. Number pooling then carried 408 for another decade before the CPUC said the earlier plan was out of date and started again.

Time zone and daylight saving time

Area code 408 uses Pacific Time. The tz database zone table lists the zone America/Los_Angeles with the label "Pacific." Federal rules describe the boundary between the mountain and Pacific zones as running along the Arizona and California boundary to Mexico (49 CFR 71.9), and place the part of the continental United States west of that line in the Pacific zone (49 CFR 71.10). San Jose lies well west of that line.

NIST says daylight saving time begins at 2:00 a.m. on the second Sunday of March and ends at 2:00 a.m. on the first Sunday of November, under rules enacted by the Energy Policy Act of 2005. The NIST page lists Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands, and Arizona as places that do not observe it, and California is not on that list. In 2026, NIST gives March 8 and November 1 as the change dates.

How to dial a 408 number

North American numbers have three parts: a country code, a three-digit area code, and a seven-digit local number. NANPA says the ITU assigned country code 1 to the NANP area.

The CPUC says that after October 20, 2012, all calls from the 408 area code must be dialed as 1 plus the area code plus the seven-digit number, including calls within 408 that once needed only seven digits. Calls dialed another way are not completed, and the caller is told to hang up and dial again. Its 2012 releases add that callers using a mobile phone do not have to include the 1, and that you can still dial three digits to reach 911, as well as 211, 311, 411, 511, 611, 711, and 811. The CPUC dialing material dates from 2012, so confirm the current rule with your provider.

The CPUC asked customers to reprogram equipment that stores a seven-digit number, and listed life safety systems, fax machines, Internet dial-up numbers, alarm and security systems, speed dialers, gates, mobile phone contact lists, call forwarding settings, and voicemail services.

Caller ID and scams with a 408 number

The FTC warns that "Scammers can make any name or number show up on your caller ID." That is called spoofing. Scammers can also match the first six digits of your own number, which the FTC calls neighbor spoofing.

• If you pick up and do not recognize the caller, the FTC advises that you hang up.
• Letting an unknown call go to voicemail is one option.
• The FTC says call blocking is your best defense against unwanted calls.

The sources checked do not say that 408 numbers are targeted more than others. A 408 number shows the code that was assigned, not who is calling or where they are. Because 669 serves the same territory, a 408 caller ID is also not a sign that a caller has had a number for longer than a 669 caller.

Choosing a 408 number for a business

408 is the original code for San Jose and Santa Clara County, but since November 20, 2012 new services in the same area may be assigned 669 numbers. A new line may carry 669 instead of 408, and neither code shows which part of the territory the business is in.

Because the two codes share one territory, route calls by team or extension, not by area code. Ask your provider which code a new line gets, since that depends on its current inventory.

Whether a specific 408 number can be assigned to your business depends on your phone provider and its current inventory. This guide does not make claims about availability.

Important: Confirm availability with your provider before you plan a campaign or print a number on materials.

Before you use a 408 number

• Confirm the number is available from your provider, and get its terms in writing.
• Ask who owns the number and whether it can be moved to another provider if you switch.
• Ask whether a new line would be a 408 or a 669 number. Both serve the same territory.
• Set every system to dial 1 plus the area code plus the number, including PBXs, fax machines, alarms, gates, call forwarding, and voicemail, as the CPUC advises.
• Print the full number, with area code, on stationery, cards, and advertising.
• Route calls by team or extension, because 408 and 669 share one territory.
• Check each site's address. The CPUC names cities, not street boundaries, and only a portion of Palo Alto is in 408.
• Plan for caller ID. A 408 number does not prove who is calling, and neighbor spoofing copies the first six digits of your own number.

Related guides and tools

• 415 area code guide: San Francisco, the code 408 was split from in 1959.
• 619 area code guide: San Diego, another California code that the CPUC relieved by sharing its territory with a second code.
• 916 area code guide: Sacramento, another Northern California code, for comparison with San Jose.
• 503 area code guide: Portland, another West Coast metro, for comparison with San Jose.
• 213 area code guide: Los Angeles, another California code, for comparison with San Jose.
• What is a DID number?: what a DID is, local versus toll-free types and porting rules.
• Business phone number porting: how number porting works, how long it takes and how to prepare.
• Full list of U.S. area codes by state, with the overlay codes and time zone for every code.
• Browse all U.S. area code guides, including overlay codes that do not have their own guide yet.
• Business phone system and call routing for local numbers in San Jose.

Frequently asked questions