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 Fenwick & West LLP, Vierra Magen Marcus, LLP, and Knobbe Martens Olson & Bear, LLP.

Top cities in California

All practitioners in California

James Trosino

Reg. 39862

Patent attorney

Vierra Magen Marcus, LLP

San Francisco, CA · 94105

415-489-4126

David R. Trossen

Reg. 59406

Patent attorney

Knobbe Martens Olson & Bear, LLP

San Francisco, CA · 94104-4448

415-954-4114

Timothy A. Trost

Reg. 80052

Patent attorney

Reichman Jorgensen Lehman and Feldberg LLP

Redwood City, CA · 94065

213-509-3803

Becky L Troutman

Reg. 36703

Patent attorney

Winston & Strawn LLP

San Francisco, CA · 94111

415-591-1401

Cindy L Troutt

Reg. 71192

Patent agent

Canon U.S.A., Inc.

Irvine, CA · 92618

949-932-3219

Stuart B Truax

Reg. 76962

Patent agent

Baker Botts LLP

San Francisco, CA · 94111

415-291-6242

Anthony M Truchard· II

Reg. 56615

Patent attorney

Truchard Vineyards

Napa, CA · 94559

707-253-7153

Sabra-Anne R Truesdale

Reg. 55687

Patent attorney

Western Digital

San Jose, CA · 95119

408-717-8592

Nathaniel T. Trujillo

Reg. 80137

Patent agent

Fenwick & West LLP

Mountain View, CA · 94041

650-335-4923

Bobby Khai Truong

Reg. 37499

Patent attorney

San Jose, CA · 95129

408-255-9114

Francis K Truong

Reg. 62548

Patent agent

San Jose, CA · 95116

408-710-2939

Jason V Truong

Reg. 53704

Patent attorney

Canon USA, Inc.

Irvine, CA · 92612-2411

949-932-3145

Lawrence Q Truong

Reg. 50884

Patent attorney

San Diego, CA · 92129

858-663-1349

Susan Marjorie Truscott

Reg. 56628

Patent agent

Hercules, CA · 94547

510-724-4884

Caressa Tsai

Reg. 800154

Limited recognition

Morrison Foerster LLP

San Francisco, CA · 94102

415-268-7102

Felix T Tsai

Reg. 69179

Patent attorney

San Francico, CA · 94102

650-888-3574

Hung-Wei Tsai

Reg. 62601

Patent attorney

Apple Inc.

Cupertino, CA · 95014

858-319-4640

Jennifer C Tsai

Reg. 69487

Patent attorney

Irvine, CA · 92614

949-922-9877

Olivia J Tsai

Reg. 58350

Patent attorney

San Francisco, CA · 94109

555-555-5555

Patricia Tsai

Reg. 72642

Patent attorney

Pittsburg, CA · 94565

678-888-2258

Philip Tsai

Reg. 65280

Patent agent

Foster City, CA · 94404

650-578-9330

Terry Tanien Tsai

Reg. 57002

Patent attorney

Arent Fox LLP

Los Angeles, CA · 90013

213-443-7681

Dominic Tsang

Reg. 64741

Patent attorney

Santa Clara, CA · 95051

408-868-4096

Fredrick S. Tsang

Reg. 68680

Patent attorney

Fenwick & West LLP

Mountain View, CA · 94041

650-335-7982

Mei Tsang

Reg. 56122

Patent attorney

Umberg Zipser LLP

Irvine, CA · 92614

949-679-0052

Chein-Hwa S Tsao

Reg. 54502

Patent agent

CH Emily LLC

San Jose, CA · 95120

408-323-1608

Jonathan J Tsao

Reg. 61241

Patent agent

Ascenda Law Group, PC

San Jose, CA · 95131

408-547-7040

Kevin C. Tsao

Reg. 81937

Patent agent

Irvine, CA · 92602

714-686-7788

Patricia I Tsao

Reg. 50713

Patent attorney

Morrison & Foerster

San Francisco, CA · 94105

415-268-6642

Ariana Y Tse

Reg. 84624

Patent agent

Schox Patent Group

San Francisco, CA · 94107

888-775-9990

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.