310 vs 424 Area Code: Key Differences, Coverage, and Which One to Choose (2026)
Los Angeles has one of the most fragmented area code maps in America, and the 310 vs 424 question sits at the center of it. Both codes ring the same stretch of coastal LA County — Santa Monica, Beverly Hills, Malibu, Torrance, and the beach cities — yet Angelenos treat 310 as the “real” Westside code and 424 as the newcomer. When the overlay arrived in 2006, it sparked genuine cultural outrage: columnists mocked Westsiders for having to dial ten digits, and the stereotype of the status-obsessed 310 stuck around for years.
Two decades later, the dust has settled. Here is what actually separates 310 from 424: where they serve, why the overlay exists, how dialing works, and which one you should pick.
310 vs 424 at a Glance
| 310 Area Code | 424 Area Code | |
|---|---|---|
| Region | Westside & South Bay, Los Angeles County | Same region (identical) |
| Key cities | Santa Monica, Beverly Hills, Malibu, Torrance, Compton, Redondo Beach, Manhattan Beach, El Segundo, Culver City, Inglewood, Catalina Island | Same cities (identical) |
| Type | Geographic split from 213 (1991) | Overlay on 310 (2006) |
| Introduced | November 2, 1991 | August 26, 2006 |
| Time zone | Pacific (UTC-8 / UTC-7 DST) | Pacific (UTC-8 / UTC-7 DST) |
| Dialing | 10 digits mandatory | 10 digits mandatory |
| Availability | Scarce for new lines | Readily available |
Where Each Code Serves
310 and 424 serve exactly the same territory. Both cover the western and southwestern portions of Los Angeles County: the Westside (Santa Monica, Beverly Hills, West Los Angeles, Malibu, Pacific Palisades, Brentwood, Culver City, Marina del Rey) and the South Bay (Torrance, Redondo Beach, Manhattan Beach, Hermosa Beach, El Segundo, Hawthorne, Inglewood, Gardena, Carson, Compton, San Pedro), plus Santa Catalina Island offshore.
The region is economically and culturally distinctive: entertainment studios in Santa Monica and Culver City, aerospace in El Segundo, the tech corridor of “Silicon Beach,” high-end retail along Rodeo Drive, and the port complex at San Pedro. It is also far more diverse than the Westside stereotype suggests — Compton, Inglewood, Hawthorne, Lawndale, and San Pedro are all 310/424 territory too.
How did one region end up with two codes? Area code 310 was created on November 2, 1991, as a split from the original 213, which once covered all of Los Angeles. In 1997, the southeastern portion of 310 (the Gateway Cities from Long Beach to Whittier, plus parts of Orange County) split off to become area code 562. The remaining 310 region kept growing — mobile phones, pagers, and the Westside’s density kept eating numbers — and by the late 1990s regulators knew relief was coming.
The original plan was dramatic: split 310 geographically at Imperial Highway, with the South Bay getting the new 424. South Bay governments and businesses revolted — they had just changed codes in the 562 split and faced enormous costs for new stationery, signage, and business cards. The California Public Utilities Commission backed down and instead implemented 424 as an overlay across the entire 310 region, announced in 1999 and activated on July 26, 2006 (numbers assignable from August 26, 2006). It was the first area code overlay in California history, and the ten-digit dialing it required is what set off the cultural firestorm.
Key Differences Between 310 and 424
Age and image. Area code 310 has been the Westside’s code since 1991, and in LA’s status-conscious culture it became shorthand for beach-adjacent affluence — the “310 lifestyle” of Santa Monica, Malibu, and Beverly Hills. Area code 424, arriving in 2006 as an administrative overlay, never acquired that mythology. Functionally they are twins; culturally, 310 is the established name brand.
Availability. This is the practical difference that matters. After 35 years of assignments, fresh 310 numbers are hard to come by. New lines in the region are routinely issued with 424 prefixes. If a carrier offers you a Westside number today, it will very likely be 424 — not because 424 is inferior, but because it is where the open inventory lives.
Nothing geographic. It bears repeating because the misconception is so common: there is no Westside/South Bay split between the codes, no coastal/inland divide, no Santa Monica-vs-Torrance distinction. A 424 number in Beverly Hills and a 310 number in the same building are on the same network, the same rate centers, the same local calling area.
Nothing technical. Call quality, pricing, texting, and coverage are identical. The CPUC’s overlay order kept every existing 310 number unchanged and confirmed that what counts as a local call did not change — only the dialing procedure did.
Overlays and Dialing Rules
The 310/424 region is a classic overlay complex: two codes, one geography. Because the area code alone no longer identifies a unique destination, 10-digit dialing is mandatory for all local calls — a rule in place since the overlay took effect in 2006.
What to know:
- Local calls: dial all 10 digits (area code + number), even to your neighbor. The “1” prefix is generally not required for local calls on mobile carriers but is on some landlines.
- Long distance: 1 + area code + number.
- International: exit code + 1 + the 10-digit number (e.g., +1 424-555-0188).
- Existing numbers never changed when 424 was added — the overlay was chosen specifically to avoid forcing millions of number changes.
One historical footnote worth knowing: a 562 overlay for 310’s cell phones was actually planned back in 1995, but the CPUC converted it to a geographic split instead, partly over fears that an overlay would disadvantage smaller carriers’ customers with mandatory ten-digit dialing. A decade later, the 424 overlay went ahead anyway — and ten-digit dialing became the California norm.
Which Should You Choose?
Choose 310 if you can get one and the Westside brand equity matters. For entertainment, real estate, hospitality, and lifestyle businesses where a Santa Monica or Beverly Hills identity is part of the pitch, a 310 number still carries a subtle signal. Expect to hunt: recycled 310 inventory, number brokers, or porting an existing line are the realistic paths.
Choose 424 if you need a Westside or South Bay number now. For startups in Silicon Beach, restaurants, contractors, medical offices, and anyone who just needs the phone to ring, 424 is the sensible default — same coverage, same cost, available today from every major carrier and VoIP provider. The cultural stigma that greeted the overlay in 2006 has largely evaporated; most Angelenos under 40 have never known a time without it.
Match the code to the market, not the myth. If your customers are in Torrance or Compton, either code reads as local — because both are. Do not pay a premium for 310 unless the brand signal genuinely earns it back.
Scam Notes
The 310/424 region’s affluence makes it a magnet for spoofing. Watch for:
- Fake utility and “Southern California Edison” shutoff scams threatening same-day disconnection unless you pay by gift card or wire.
- Spoofed 310 numbers impersonating Beverly Hills businesses, talent agencies, or medical offices — the code’s prestige is the lure.
- Rental scams targeting newcomers hunting for Westside apartments, using local numbers to seem legitimate.
As always, the area code authenticates nothing. Verify unexpected callers through independently published numbers, never through a callback number the caller provides.
Time zone note: both codes are in the Pacific Time Zone (UTC-8 standard, UTC-7 daylight), observing daylight saving time. When calling LA from the East Coast, remember the three-hour difference.
Frequently Asked Questions
What is the difference between 310 and 424 area codes?
There is no geographic difference — both serve the same Westside and South Bay region of Los Angeles County. Area code 310 is the original 1991 code; 424 is a 2006 overlay added when 310 numbers ran short.
Is 424 also Los Angeles?
Yes. Area code 424 covers the same Los Angeles County territory as 310, including Santa Monica, Beverly Hills, Malibu, Torrance, and the South Bay beach cities.
Why was 424 created?
The 310 region was running out of numbers by the late 1990s. After South Bay communities rejected a geographic split, regulators implemented 424 as an overlay across the entire 310 area instead, preserving everyone’s existing numbers.
Do I have to dial the area code for local calls in 310/424?
Yes. Ten-digit dialing is mandatory for all local calls because two area codes share the same region.
Can I still get a 310 number?
It is difficult but possible through recycled carrier inventory, number brokers, or porting. Most new lines in the region are issued with 424 numbers.
Conclusion
The 310 vs 424 story is really about LA’s growth outrunning its phone numbers: one code since 1991, a rejected split, and California’s first overlay in 2006. Today they are geographic twins — same cities, same costs, same dialing rules. 310 buys you heritage; 424 buys you availability. Pick the one that serves your actual goal, and either way, you are unmistakably Westside.