Area code 424 is an overlay of area code 310, serving West Los Angeles, the Westside, the South Bay and the L.A. beach cities; it was the first overlay in California.
The essentialsNumbering data from NumberResearch · as of 2026-09-17
Place
West LA / South Bay (overlay)
Type
geographic
Status
in service
In service since
2006
Country
United States
Status, dates and counts are read from NumberResearch (NANPA / CNAC / FCC records), as of 2026-09-17. Assignment records show initial assignees, not the carrier serving a number today.
Where 424 is
West Los Angeles, the Westside, the South Bay and L.A. County beach cities (shares 310's geography).
Communities served wholly or partly by 424:
Santa MonicaBeverly HillsCulver CityTorranceInglewoodManhattan BeachRedondo BeachEl SegundoMalibu
As an overlay, 424 shares the same geography as 310; the community list mirrors 310.
How it relates to other codes
The codes 424 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?
Overlay · 2006310West LA & South Bay424 is the all-services overlay of 310. New 424 numbers first became assignable on August 26, 2006; mandatory 1+10-digit dialing had begun a month earlier, on July 26, 2006. California's first overlay.
Related · 1991213Downtown & Central LA310, the code 424 overlays, was itself split from 213 on November 2, 1991.
History
2006-07-26
Mandatory 1+10-digit dialing began across the 310/424 region (12:01 a.m.), ahead of new-code assignment.
Source: CPUC news release 58447 (primary)
2006-08-26
New 424 numbers first became assignable — the all-services overlay of 310, authorized by CPUC Decision D.05-08-040.
Source: CPUC news release 58447 (primary)
What's changing. Active — 424 is itself the overlay code layered on 310 (in service since August 26, 2006).
How full it is
Prefixes assigned
475
Prefixes available
325
Projected exhaust
2043 Q1
Prefix-assignment counts describe allocation to carriers, not how many individual numbers are in use. Full technical records: NumberResearch ↗.
Live status, dates, assignment counts and exhaust forecast — data as of 2026-09-17 (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.