Area Code for Oakland

Oakland’s area code is 510 — established September 2, 1991, when the East Bay was carved out of the original 415 territory that once covered all of Northern California.

A second code, 341, was overlaid onto the same geography in July 2019 by the California Public Utilities Commission (CPUC) when the 510 number pool approached exhaustion. Both codes serve identical territory and calls between them are local.

The surrounding Bay Area adds more context: 925 covers the inland East Bay (Concord, Walnut Creek, Pleasanton, Livermore) after splitting from 510 in 1998. 415 and 628 cover San Francisco across the bay. Understanding which code belongs to which East Bay sub-region matters for businesses setting up local presence, configuring phone systems, and spotting spoofed calls.

What’s the area code for Oakland?

Oakland and the western East Bay use two active area codes that cover the same territory.

Code	Established	Type	Coverage
510	Sep 2, 1991	Original	Oakland, Berkeley, Fremont, Hayward, Alameda, Richmond + western Alameda & Contra Costa counties
341	Jul 22, 2019	Overlay	Same geographic territory as 510

Both codes are local to each other — a call from a 510 number to a 341 number is a local call, not long distance.

Since the 341 overlay launched, all calls within the zone require 10-digit dialing (area code + 7-digit number). Ten-digit dialing became mandatory on June 22, 2019 — one month before the first 341 numbers became available. Emergency services (911) and N11 codes (211, 311, 411) remain three digits.

Sources: NANPA, CPUC, FCC.

East Bay area codes by region

The East Bay spans multiple distinct codes depending on geography. Here is how the map breaks down.

Oakland proper (510 / 341)

Area code 510 covers Oakland’s city limits in full. All Oakland neighborhoods — Downtown, Uptown, Jack London Square, Fruitvale, Rockridge, Grand Lake, Temescal, West Oakland, East Oakland — fall under 510/341.

Oakland is the seat of Alameda County and the third-largest city in the Bay Area (~440,000 residents).

Berkeley and UC Berkeley (510 / 341)

Berkeley shares the 510/341 zone with Oakland. UC Berkeley — one of the top public research universities in the world — operates under 510. The campus, its affiliated labs (Lawrence Berkeley National Laboratory), and surrounding city all carry 510/341 numbers.

Alameda Island and San Leandro (510 / 341)

The city of Alameda (the island city directly south of Oakland, connected by tunnels and bridges) is entirely within the 510/341 zone. San Leandro, bordering Oakland to the south, is also in 510/341.

Hayward (510 / 341)

Hayward (~160,000 residents), south of San Leandro along the bay, carries 510/341. Cal State University East Bay (CSUEB) is in Hayward under 510.

Richmond (510 / 341)

Richmond, in western Contra Costa County, is in the 510/341 zone. The Port of Richmond and the Chevron Richmond refinery both operate under 510.

Fremont (510 / 341)

Fremont (~240,000 residents) is the largest city in Alameda County and sits at the southern end of the 510/341 zone. Tesla’s primary US manufacturing plant — the Fremont Factory — carries a 510 number.

Inland East Bay — 925 territory

Once you cross the Berkeley Hills heading east, the area code changes to 925.

City	County	Area Code
Concord	Contra Costa	925
Walnut Creek	Contra Costa	925
Antioch	Contra Costa	925
Livermore	Alameda	925
Pleasanton	Alameda	925
San Ramon	Contra Costa	925

925 was split from 510 on March 14, 1998. The Berkeley Hills serve as the natural dividing line between 510 and 925.

History of Oakland area codes

Oakland’s phone history follows Northern California’s broader pattern of one original code expanding and splitting as population grew.

1947 — 415 assigned. AT&T’s Bell System partitioned the US into 86 numbering plan areas. California received three original codes: 213 (Southern CA), 916 (Sacramento and Central Valley), and 415 (all of Northern California). Oakland, Berkeley, and the entire East Bay dialed 415.

1991 — 510 split from 415. By the late 1980s, fax machines, pagers, and population growth were exhausting 415 number combinations. On September 2, 1991, the East Bay was carved out with its own code: 510. The split covered Oakland, Berkeley, Fremont, Hayward, Alameda, Richmond, and the western Contra Costa corridor. It was a geographic split — existing 415 customers in the East Bay had to change their numbers to 510.

1998 — 925 split from 510. Seven years later, the inland East Bay outgrew its own pool. On March 14, 1998, area code 925 was created from the eastern portion of 510. The Berkeley Hills served as the dividing line: west of the hills stayed 510, east of the hills moved to 925. Cities affected: Concord, Walnut Creek, Antioch, Livermore, Pleasanton, and San Ramon.

2016–2019 — 341 overlay. By 2016, the California Public Utilities Commission projected that the 510 pool would exhaust by Q2 2019. Rather than another geographic split (which forces number changes), NANPA proposed an overlay — a new code serving the same geography. NANPA formally proposed code 341 in May 2017. CPUC approved the relief plan on June 21, 2018. Mandatory 10-digit dialing launched June 22, 2019. First 341 numbers became available July 22, 2019.

Sources: NANPA, CPUC Decision 18-06-015, FCC.

510 as Oakland and East Bay identity

No area code in the Bay Area carries the same community weight as 510 — not even the older 415 across the water.

When 510 launched in 1991, it gave the East Bay its first distinct dialing identity after four decades of sharing 415 with San Francisco. For Oakland, Berkeley, and the surrounding cities, 510 became a marker of place.

Oakland celebrates 510 Day on May 10 each year. The area code appears on murals across Oakland and Berkeley, on clothing brands (510 Brand sells East Bay gear built entirely around the three digits), and tattooed on artists at Oakland shops like Five and Dime Tattoo — which was named after 510 itself.

When the 341 overlay arrived in 2019, community resistance was real. Oakland Mayor Libby Schaaf put it directly: “510 has always been East Bay. This is going to be one more thing that separates the OG’s from the newcomers.” Residents said the code appeared “on all my stuff — my business card, my social media account.” One resident: “I’m a 510 all day like it’s an identification.”

The cultural depth reflects Oakland’s outsized creative output relative to its size. The East Bay hip-hop scene gave the country Too Short, MC Hammer, and Souls of Mischief — all coming up in the 510. The Oakland Raiders gave the 510 a national platform in NFL broadcasting for decades. The Golden State Warriors played Oakland’s Oracle Arena from 1971 to 2019 under 510 before moving to San Francisco. UC Berkeley — birthplace of the Free Speech Movement and consistently a top-10 global university — anchors academic identity in the 510.

The Black Panthers were founded in Oakland in 1966. Oakland Roots SC — the city’s soccer club — wears the 510 as a badge in its branding.

For a business, a 510 number is not just a local number. It signals East Bay — and East Bay carries meaning.

Oakland area code spam and scams

The 510 and 341 codes attract spoofing for the same reason 415 does: they signal “local” to Bay Area recipients, which increases answer rates for robocallers.

Common scam patterns targeting East Bay numbers in 2025–2026:

Auto warranty fraud accounts for the highest complaint volume — approximately 15% of 510 spam reports. Callers impersonate vehicle service contract companies.

IRS and government impersonation. Callers claim outstanding tax debt or Social Security violations with arrest threats. These remain the highest-volume phone fraud category per the FCC.

Fake delivery notifications. Given Oakland’s position as a major port city — the Port of Oakland is the fifth-busiest container port in the US — fake package and freight delivery calls are particularly plausible to East Bay recipients.

Port and logistics fraud. Callers impersonate Port of Oakland customs agents or freight forwarders, targeting import/export businesses with fake fee demands or documentation scams.

UC Berkeley tuition fraud. Callers impersonate UC Berkeley financial aid offices targeting students and families with fake tuition payment requests, scholarship offers, or financial hold warnings.

Neighbor spoofing drives approximately 73% of robocall fraud nationwide. Scammers generate 510 or 341 numbers to appear local, increasing answer rates. The FCC mandated STIR/SHAKEN authentication starting in 2021 to address this.

STIR/SHAKEN assigns attestation levels to calls: A-attestation (full verification — caller is authorized to use the number), B-attestation (partial — carrier can identify the customer but not verify the number), and C-attestation (gateway — unverified, often international). Calls at B or C level frequently trigger “Potential Spam” labels on modern smartphones.

DialPhone provisions 510 and 341 numbers with A-attestation, so legitimate East Bay business calls display as verified rather than flagged. For businesses calling into Oakland’s logistics, healthcare, and education sectors — where spam filters are high — this distinction affects whether calls get answered.

Report suspicious 510/341 calls to the FCC Consumer Complaint Center.

How to get an Oakland business phone number

Getting a 510 or 341 virtual phone number does not require a physical Oakland office or California business license. VoIP providers provision virtual numbers through the national DID pool.

Step 1 — Choose your code. 510 carries stronger East Bay identity; 341 has broader number availability. Both are local to East Bay recipients and carry identical call routing.

Step 2 — Select a DialPhone plan. Review options at DialPhone pricing. All plans include local DID numbers. Enterprise plans include number porting if you are moving an existing 510 number from another carrier.

Step 3 — Claim your number. Search the available 510 and 341 inventory during signup. Pick your preferred prefix combination.

Step 4 — Configure routing. Set call forwarding, IVR menus, voicemail-to-text, and the AI receptionist to handle after-hours or overflow calls. For healthcare clients in the Kaiser/Sutter network, configure HIPAA-compliant call recording.

Step 5 — Go live. Your DialPhone 510 or 341 number is live immediately. Porting an existing Oakland number from another carrier takes 2–4 business days — see the number porting guide for the exact paperwork and timeline.

All DialPhone 510 and 341 numbers include STIR/SHAKEN A-attestation by default. See DialPhone business phone and start a free trial.

Famous companies in East Bay area codes

The 510 zone is home to a range of global companies across healthcare, technology, manufacturing, and consumer goods.

Kaiser Permanente (HQ: Oakland, 510) — the largest managed care organization in the US, founded in Oakland in 1945. Kaiser employs more than 300,000 people nationwide and operates its global headquarters under a 510 number in downtown Oakland.

Clorox Company (HQ: Oakland, 510) — founded in Oakland in 1913, Clorox is a Fortune 500 consumer goods company headquartered on Broadway in downtown Oakland with 510 main lines.

Pandora Media (HQ: Oakland, 510) — the streaming music pioneer was headquartered in Oakland before its SiriusXM acquisition. Pandora’s Oakland roots placed it firmly in the 510 tech wave.

Pixar Animation Studios (Emeryville, 510) — the Academy Award–winning studio behind Toy Story, Finding Nemo, and The Incredibles has operated from Emeryville — inside the 510/341 zone — since 1986. Pixar’s campus at 1200 Park Avenue, Emeryville carries a 510 address.

Tesla (Fremont Factory, 510) — Tesla’s primary US vehicle manufacturing plant, the Fremont Factory, operates in Fremont under a 510 address. The factory produces the Model 3, Model Y, Model S, and Model X.

Peet’s Coffee (Berkeley origin, 510) — founded by Alfred Peet in Berkeley in 1966, Peet’s predates Starbucks by seven years. The original Berkeley location on Vine Street — still open — carries a 510 number. Peet’s is credited with teaching the founders of Starbucks their craft.

These organizations span healthcare, consumer goods, animation, clean energy, and the specialty coffee that seeded the entire third-wave coffee movement — all under 510.

For California businesses targeting East Bay enterprise clients, sharing an area code with Kaiser, Clorox, and Pixar is a credibility signal that a toll-free number does not provide.

Oakland area code FAQ

Oakland area code FAQ

What is the area code for Oakland? +

Oakland uses two area codes: 510 and 341.

510 is the original code, established September 2, 1991, when it split from area code 415 to serve the East Bay. 341 is an overlay added July 22, 2019, by the California Public Utilities Commission (CPUC) when the 510 number pool was projected to exhaust. Both codes cover the same geography — Oakland, Berkeley, Fremont, Hayward, Alameda, and Richmond — and calls between them are local, not long distance.

Is 341 an Oakland area code? +

Yes. 341 is a full Oakland area code covering the same geographic territory as 510.

The CPUC approved the 341 overlay after NANPA projected 510 number exhaustion in Q2 2019. Ten-digit dialing became mandatory on June 22, 2019, and new 341 numbers became available on July 22, 2019. Any number assigned in the East Bay after that date may carry either a 510 or 341 prefix.

What area code is inland East Bay — Concord, Walnut Creek, Pleasanton? +

Inland East Bay uses area code 925.

925 was split from 510 on March 14, 1998, along the natural border of the Berkeley Hills. Everything west of the hills stayed in 510; everything east moved to 925. Cities in the 925 zone include Concord, Walnut Creek, Antioch, Livermore, Pleasanton, and San Ramon. Unlike 510, area code 925 has not required an overlay and remains a single-code zone.

What is the area code for San Francisco, across the bay from Oakland? +

San Francisco uses area codes 415 and 628.

415 is one of the original 86 North American codes assigned in 1947 — it originally covered all of Northern California before a series of splits. 628 is a 2015 overlay covering the same SF and Marin County geography. Oakland's 510 was actually carved out of the old 415 territory in 1991. See the full SF guide at /area-codes/415.

Do I need to dial 10 digits for Oakland calls? +

Yes. Since June 22, 2019, all calls within the 510/341 zone require 10-digit dialing: area code + 7-digit number.

Before the 341 overlay, local East Bay calls within 510 only needed 7 digits. After the overlay, the same local call requires 510-XXX-XXXX or 341-XXX-XXXX. This does not create a long-distance charge — only the dialing format changed. Business phone systems, door intercoms, and fax machines configured for 7-digit dialing needed to be updated in 2019.

Why is the 510 area code a cultural identity in Oakland? +

510 became an Oakland identity marker in part because it was the first code to separate the East Bay from San Francisco.

When 510 launched in 1991, it gave Oakland, Berkeley, and the East Bay their own distinct dialing identity after decades of sharing 415 with SF. The code appears on Oakland murals, clothing brands, tattoos, and business names. Oakland celebrates 510 Day on May 10. When the 341 overlay arrived in 2019, many East Bay residents resisted — not for technical reasons, but because losing a 510 number felt like losing an identity badge.

How do I get an Oakland 510 business phone number? +

You can get a 510 or 341 virtual phone number from DialPhone without a physical Oakland address.

DialPhone provisions 510 and 341 numbers with STIR/SHAKEN A-attestation — the highest verification level — so your calls display as verified rather than flagged as potential spam. Setup takes minutes. Number porting from another carrier takes 2–4 business days. See the free trial at /pricing/free-trial.

What famous companies are headquartered in Oakland's 510 area code? +

Several major companies headquarter in the 510 zone.

Kaiser Permanente (Oakland HQ), Clorox (Oakland HQ), Pandora (Oakland), Pixar Animation Studios (Emeryville), Tesla's primary US manufacturing plant (Fremont), and Peet's Coffee (Berkeley origin, 1966). UC Berkeley — a top-5 global research university — also operates under 510. These names give the 510 code strong commercial credibility for East Bay businesses.

Get an Oakland business number

Whether you are establishing a local presence for an East Bay sales team, porting an existing 510 number to a modern VoIP platform, or setting up an AI receptionist to answer Oakland calls around the clock — DialPhone provisions 510 and 341 numbers with A-attestation verification and median port time of 2–4 business days.

• Start a free trial — claim your 510 or 341 number
• View all DialPhone plans and pricing
• Business phone features overview
• AI receptionist for after-hours Oakland calls
• Number porting guide — move your existing Oakland number

Related area code pages: 510 Oakland · 415 San Francisco · California area codes