California

Patent attorneys in California

California hosts 9,553 active patent practitioners registered with the USPTO Office of Enrollment and Discipline. Patent attorneys and patent agents can both prepare and file patent applications, but only patent attorneys can also offer legal advice on prosecution strategy, freedom-to-operate analyses, and infringement opinions in California. Practitioners are concentrated across 20 cities, with the largest clusters in the metros listed below. Notable firms with multiple registered practitioners in the state include Mammoth Biosciences, Loza & Loza LLP, and Intellectual Property Officer 3.

Top cities in California

All practitioners in California

Erin K. Soto

Reg. 72921

Patent agent

Mammoth Biosciences

Brisbane, CA · 94005

650-294-8583

Kevin L Soules

Reg. 66033

Patent attorney

Loza & Loza LLP

Upland, CA · 91786

877-406-5164

Prabakaran Soundararajan

Reg. 71237

Patent agent

Intellectual Property Officer 3

Davis, CA · 95618

207-812-8053

Patrick L. Soung

Reg. 84436

Patent agent

Saratoga, CA · 95070

408-913-0098

Alex Sousa

Reg. 50671

Patent attorney

Santa Clara, CA · 95051

408-243-3659

Melissa S Souza

Reg. 65277

Patent attorney

Hewlett-Packard Company

Palo Alto, CA · 94304-1112

650-857-2513

Joanna M. Soyring

Reg. 83253

Patent attorney

KPPB, LLP

Long Beach, CA · 90806

949-288-5188

Susan M Spaeth

Reg. 35687

Patent attorney

Kilpatrick Townsend & Stockton, LLP

Menlo Park, CA · 94025

650-324-6335

Thomas M Spahn

Reg. 67794

Patent attorney

Sullivan & Cromwell LLP

Palo Alto, CA · 94303

510-610-1632

Astrid R Spain

Reg. 47956

Patent attorney

D2G Oncology, Inc.

Mountain View, CA · 94043

858-248-0610

Joshua M. Spandy

Reg. 84774

Patent attorney

San Diego, CA · 92122

858-353-7778

Jonathan David Spangler

Reg. 40182

Patent attorney

Sprangler IP Law

San Diego, CA · 92106

858-243-0029

Joseph S Spano

Reg. 63296

Patent attorney

Spano Law Group

Burlingame, CA · 94010

650-307-0332

Matthew J Spark

Reg. 43453

Patent attorney

Calyx Law LLP

San Francisco, CA · 94105-2448

213-474-0976

Paul J Spatafore

Reg. 66402

Patent attorney

Cepheid

Sunnyvale, CA · 94089

425-205-0472

Teresa Spehar

Reg. 51281

Patent attorney

San Diego, CA · 92130

858-354-5854

Howard L Speight

Reg. 37733

Patent attorney

Napa, CA · 94558

713-465-2340

Charles F Spence

Reg. 73634

Patent agent

Arcadia, CA · 91007

627-327-2206

Lee Spencer

Reg. 43353

Patent attorney

Taylor Made- Adidas Golf

Carlsbad, CA · 92008

760-918-6000

Ronald L. Spencer· Jr

Reg. 71946

Patent attorney

Camarillo, CA · 93011

805-217-6007

Ashley E Sperbeck

Reg. 74144

Patent attorney

Weaver Austin Villeneuve & Sampson LLP

Oakland, CA · 94607

510-663-1100

Robert Malcolm Sperry· Sr

Reg. 18053

Patent attorney

Woodland Hills, CA · 91367

818-225-1011

Laura O Spiegelman

Reg. 46345

Patent attorney

Morrison & Foerster

San Francisco, CA · 94105-2482

415-268-7540

Paul David Spiel

Reg. 75231

Patent attorney

Knobbe Martens, Olson & Bear, LLP

Irvine, CA · 92614

206-405-2032

Mark D Spiller

Reg. 65740

Patent agent

Sole Practitioner

Davis, CA · 95618

510-207-6521

Craig Spiro

Reg. 68391

Patent attorney

SAN GABRIEL, CA · 91775-2057

213-626-2776

Bradley D. Spitz

Reg. 59920

Patent attorney

San Diego, CA · 92108

619-618-6040

Kevin R Spivak

Reg. 43148

Patent attorney

Vierra Magen & Marcus LLp

San Francisco, CA · 94105

415-489-4100

Mark James Spolyar

Reg. 42164

Patent attorney

San Francisco, CA · 94114

Brian J Springer

Reg. 72109

Patent agent

Saugus, CA · 91350

661-714-0816

Common questions

Do I need a patent attorney based in California?

No. Every USPTO-registered patent practitioner is licensed to file applications on behalf of inventors in any state, regardless of where the practitioner's office is. Choosing a California-based practitioner can simplify in-person inventor signings, local meetings, and same-time-zone calls, but it is not a legal requirement.

How many patent attorneys are licensed in California?

9,553 active USPTO-registered patent practitioners list a California office address on the OEDCI roster. This includes both patent attorneys (who can also offer legal advice) and patent agents (who can prepare and file patents but not offer broader legal advice).

What is the difference between a patent attorney and a patent agent?

Both pass the USPTO Patent Bar and can prepare, file, and prosecute patent applications. Only patent attorneys also hold a state bar license, meaning they can additionally offer legal advice on infringement, licensing, and litigation strategy. Patent agents tend to charge less per hour and are common at large in-house IP departments.