North American Numbers Source-cited · ownership disclosed
Area code
408
In service
United States · since 1959

San Jose

Area code 408 serves most of Santa Clara County and part of northern Santa Cruz County, centered on San Jose. It was split from 415 in 1959 and is overlaid by area code 669.

The essentials Numbering data · NumberResearch · as of 2026-09-18
Place
San Jose
Type
geographic
Status
in service
In service since
1959
Projected exhaust
2056 Q1

Status, dates and counts are read from NumberResearch (NANPA / CNAC / FCC records). Assignment records show initial assignees, not the carrier serving a number today.

A · Where it is

Where 408 is

Most of Santa Clara County and northern Santa Cruz County (South Bay)..

Communities served wholly or partly by 408:

San JoseSunnyvaleSanta ClaraCupertinoMilpitasLos GatosGilroy

Representative list; additional Santa Clara County communities are served.

B · Relationships

How it relates to other codes

The codes 408 was split from, spawned, or shares its area with. A split divides the map and changes some numbers; an overlay shares the same ground and changes none — what's the difference?

Split from · 1959 415 San Francisco Split from 415 in a flash-cut on March 1, 1959.
Overlay · 2012 669 San Jose (overlay) All-services overlay of 408, in service November 20, 2012.
Spawned · 1998 831 Monterey / Salinas Monterey/Santa Cruz/San Benito split off from 408 on July 11, 1998.
What's changing. Overlaid by 669 (first overlay in the Bay Area); ten-digit dialing required.
C · History

How 408 got here

1959-03-01
Area code 408 split from 415 in a flash-cut; originally covered Santa Clara, Santa Cruz, Monterey, and San Benito Counties.
Source: Wikipedia
1998-07-11
Area code 831 split from 408; permissive dialing ended February 20, 1999.
Source: Wikipedia
2012-11-20
Overlay 669 in-service; permissive dialing had run April 21 to October 20, 2012.
Source: Wikipedia
D · Capacity

How full it is

Prefixes assigned
800
Prefixes available
0
Thousands-blocks assigned
2,512

Prefix-assignment counts describe allocation to carriers, not how many individual numbers are in use. Full technical records: NumberResearch ↗.

Compare 408 with another code →
Sources
Wikipedia ↗
Area codes 408 and 669
NumberResearch.org ↗
Live status, dates, assignment counts and exhaust forecast — data as of 2026-09-18 (CC BY 4.0).

Place, relationships and history above are compiled by North American Numbers from the sources listed and last checked 2026-09-18. A check date is not an expert review — see how this is made. Flag an error.