What Is 310 area code

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Last updated: April 15, 2026

Quick Answer: The 310 area code was created on November 2, 1991, as a split from area code 213 to meet growing demand in Southern California, primarily serving Los Angeles County, including cities like Santa Monica, Beverly Hills, and parts of the South Bay.

Key Facts

310 area code was introduced on November 2, 1991, splitting from 213 due to population and phone demand growth.
It primarily serves Los Angeles County, including Santa Monica, Beverly Hills, and the South Bay region.
In 1998, the 310 area was split again to create the 562 area code for Long Beach and surrounding areas.
Due to high demand, the 310 area code reached exhaustion and a overlay with 424 was introduced in 2006.
The 310 area code is now associated with prestige and exclusivity, often linked to affluent coastal communities.

Overview

The 310 area code is one of the most recognized telephone prefixes in California, serving a significant portion of Los Angeles County. Originally established to alleviate congestion in the 213 area code, 310 was introduced during a period of rapid population growth and increased mobile device usage in the late 20th century.

Today, the 310 region includes high-profile cities such as Santa Monica, Malibu, Beverly Hills, and Torrance. Its association with affluent coastal communities has elevated its cultural status, making it a desirable code for businesses and residents alike.

Creation date: The 310 area code officially launched on November 2, 1991, following a geographic split from the overburdened 213 code.
Geographic coverage: It primarily serves the Westside and South Bay regions of Los Angeles County, including cities like Culver City and Redondo Beach.
Population served: Over 2.5 million residents currently live within the 310 area code boundaries, based on recent telecommunications estimates.
Overlay introduction: To prevent number exhaustion, the 424 area code was overlaid onto the same region starting in 2006, requiring 10-digit dialing.
Cultural perception: The 310 code has become a status symbol, often associated with Southern California’s entertainment industry and coastal lifestyle.

How It Works

The 310 area code operates under the North American Numbering Plan (NANP), which governs phone numbering across the U.S., Canada, and several Caribbean nations. Its implementation and management involve coordination between the Federal Communications Commission (FCC), state regulators, and telecommunications providers.

Numbering Plan Area (NPA): The 310 area code defines a Numbering Plan Area, allowing up to 7.9 million unique phone numbers within its geographic zone.
10-digit dialing: Since the 2006 overlay with 424, all calls within the region require 10-digit dialing to ensure accurate routing.
Number exhaustion: Due to high demand, especially from mobile phones, the 310 pool neared depletion by the early 2000s, prompting the 424 overlay.
Portability: Customers can now port numbers between carriers and even retain 310 numbers when moving outside the region.
Regulatory oversight: The California Public Utilities Commission (CPUC) monitors numbering resources and approves area code changes in the state.
Future scalability: As demand grows, the 424 overlay ensures continued availability, with both 310 and 424 serving the same geographic area.

Comparison at a Glance

The following table compares the 310 area code with neighboring California area codes based on launch date, coverage, and key characteristics.

Area Code	Introduced	Primary Region	Overlay Code	Notable Cities
310	November 2, 1991	West LA, South Bay	424	Santa Monica, Beverly Hills, Torrance
213	1947	Downtown LA	323	Downtown, Boyle Heights
818	1984	San Fernando Valley	747	Burbank, Glendale, Van Nuys
562	1997	Long Beach, Norwalk	323 (partial)	Long Beach, Lakewood, Compton
424	2006	Overlay for 310	N/A	Covers same area as 310

This comparison highlights how Southern California’s explosive growth has driven repeated area code splits and overlays. The 310 and its overlay 424 reflect broader trends in urban telecommunications infrastructure, where demand from mobile devices and internet-based services continues to reshape numbering strategies.

Why It Matters

The 310 area code is more than a telecommunications identifier—it’s a cultural and economic marker with lasting significance. Its evolution reflects broader shifts in technology, population density, and regional identity across Southern California.

Business branding: Companies often seek 310 numbers to project a coastal, upscale image that resonates with clients and customers.
Residential prestige: A 310 number is frequently seen as a symbol of status, especially in real estate and entertainment circles.
Telecom planning: The 310-to-424 overlay serves as a model for how regions manage number exhaustion without disruptive geographic splits.
Mobile proliferation: The rise of cell phones dramatically increased demand, with over 80% of 310 numbers now assigned to mobile devices.
Area code preservation: Efforts to conserve numbers include reclamation programs that reclaim unused blocks from carriers.
Future challenges: As voice over IP (VoIP) and digital services grow, regulators must adapt numbering policies to non-geographic usage patterns.

Understanding the 310 area code offers insight into how infrastructure evolves alongside culture and technology. From its 1991 origins to its current dual-code system, it remains a vital part of Southern California’s identity.