Los Angeles County Area Codes (Overlay Codes are in Green) and years they became effective. Los Angeles Almanac Map.
| Year | Area Code | Serving Area |
|---|---|---|
| Oct. 1947 | 213 | All of Los Angeles County (and all of the southern third of California) |
| 1957 | 805 | Ventura, Santa Barbara, San Luis Obispo, Bakersfield, Northern L.A. County (formerly part of 213) |
| Jan. 7, 1984 | 818 | San Gabriel Valley, San Fernando Valley (formerly part of 213) |
| Nov. 2, 1991 | 310 | Western, Eastern, & Southern L.A. County (formerly part of 213) |
| Nov. 14, 1992 | 909 | Riverside, San Bernardino, Eastern San Gabriel Valley (formerly part of 714) |
| Jan. 25, 1997 | 562 | Eastern L.A. County and Long Beach (formerly part of 310) |
| June 14, 1997 | 626 | San Gabriel Valley (former 818) |
| June 13, 1998 | 323 | Area surrounding Central Los Angeles (formerly part of 213) |
| Feb. 13, 1999 | 661 | Northern L.A. County, including the Santa Clarita and Antelope Valleys (formerly part of 805) |
| Aug. 26, 2006 | 424 | Overlay for area code 310 |
| May 18, 2009 | 747 | Overlay for area code 818 |
| Feb. 23, 2021 | 840 | Overlay for area code 909 |
| Nov. 1, 2024 | 738 | Overlay for area codes 213 and 323 |
The former telephone company GTE (merged into Verizon) once inadvertantly published a telephone directory for Sierra Madre listing no home numbers.
In 1958, due to increased consumer demand for individual telephone numbers, the telephone company began phasing out old exchange names for all numeric telephone numbers or "All Number Calling" (pretty much gone by 1963). These old exchange names are remembered in Glenn Miller’s song PEnnsylvania 6-5000 and Elizabeth Taylor’s movie BUtterfield-8.
See our List of Los Angeles County Exchange Numbers gleaned from exchange names collected by the Telephone EXchange Name Project.
