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 BioTime, Inc., Entralta P.C., and Environmental Systems Research Institute, Inc..

Top cities in California

All practitioners in California

Jennifer A Fleischer

Reg. 69469
Patent attorney

BioTime, Inc.

Alameda, CA · 94501

510-521-3390

James Franklin Fleming

Reg. 57332
Patent attorney

Entralta P.C.

Thousand Oaks, CA · 91320

858-304-0202

Michelle Muller Fleming

Reg. 42913
Patent attorney

Santa Clara, CA · 95054

408-585-8977

William C Fleming

Reg. 39191
Patent attorney

Environmental Systems Research Institute, Inc.

Redlands, CA · 92373

909-793-2853 X4624

Veronica J Flesch

Reg. 80583
Patent agent

Xencor

Monrovia, CA · 91016

626-305-5900

Larry D Flesner

Reg. 37827
Patent agent

San Diego, CA · 92117-1904

858-273-8531

Karen E Flick

Reg. 44111
Patent agent

Talis Biomedical Corporation

Menlo Park, CA · 94025

650-433-3023

David L Fligor

Reg. 54784
Patent attorney

Fligor Tech Law Group

Los Altos, CA · 94022

415-310-8543

P. Matthew Flinders

Reg. 56148
Patent attorney

Roche Diagnostics Operations

Santa Clara, CA · 95050

617-699-3068

Andrew S. Flior

Reg. 65565
Patent attorney

Snell & Wilmer LLP

Costa Mesa, CA · 92626

714-427-7083

Scott A Florance

Reg. 47565
Patent attorney

Quinn, Emanuel, Urquhart, Oliver

Los Angeles, CA · 90017

213-443-3679

Eglia N Flores

Reg. 54103
Patent attorney

FACEBOOK, INC

Palo Alto, CA · 94304

650-543-7462

Brian H. Floyd

Reg. 75782
Patent agent

Power Integrations

San Jose, CA · 95138

408-414-9561

Jennifer A. Floyd

Reg. 72738
Patent agent

Wilson Sonsini Goodrich & Rosati

Sandiego, CA · 92130-3002

858-350-2267

Mark B Floyd

Reg. 41022
Patent agent

Los Gatos, CA · 95032

408-569-1967

David R. Flyer

Reg. 57480
Patent attorney

Flyer & Flyer, a Professional Law Corporation

Newport Beach, CA · 92660

949-622-8444

Brian Joseph Flynn

Reg. 78620
Patent attorney

Knobbe, Martens, Olson & Bear, LLP

Irvine, CA · 92614

858-707-4187

Brian J Flynn

Reg. 30380
Patent attorney

Sunnyvale, CA · 94088

408-469-5522

Elizabeth M Flynn

Reg. 67500
Patent agent

El Cerrito, CA · 94530

510-499-5220

Sherrie M Flynn

Reg. 62066
Patent attorney

Coleman & Horowitt, LLP

Fresno, CA · 93704

559-248-4820

Stephen B Flynn

Reg. 64143
Patent agent

Cupertino, CA · 95014

408-463-2489

Ingrid M Foerster

Reg. 36511
Patent attorney

IBM Almaden Research Center

San Jose, CA · 95120-6099

408-927-3389

Joel M Fogelson

Reg. 43613
Patent attorney

Hartmans Law

Manhattan Beach, CA · 90266

732-735-5559

Ernest D Fok

Reg. 79987
Patent attorney

Orrick Herrington & Sutcliffe LLP

Santa Monica, CA · 90401

310-633-2825

Joseph P Foley

Reg. 45757
Patent attorney

Chevron Texaco, Corp.

San Ramon, CA · 94583

925-842-1564

Cameron P Folmar

Reg. 75889
Patent attorney

The Law Office of Cameron P Folmar

Irvine, CA · 92603

949-232-3993

Brent A Folsom

Reg. 43614
Patent attorney

Haynes and Boone, LLP

Costa Mesa, CA · 92626

949-202-3013

Krisztina Foltenyi

Reg. 71197
Patent agent

National City, CA · 91950

442-888-4313

Aaron C Fong

Reg. 61923
Patent attorney

Honda Patents & Technologies NA LLC

Torrance, CA · 90501

Eric L. Fong

Reg. 66886
Patent attorney

Lafayette, CA · 94549

678-223-3664

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.
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