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 Apple Inc., Loyola Law School, and Spectro Cloud, inc.

Top cities in California

All practitioners in California

Kristin M Petherbridge

Reg. 52117

Patent agent

Altadena, CA · 91001

626-201-7325

Lee Petherbridge

Reg. 51051

Patent agent

Loyola Law School

Los Angeles, CA · 90015

213-736-8194

Joanne R Petithory

Reg. 42995

Patent agent

Union City, CA · 94587

510-507-4689

Nicholas D Petrella

Reg. 69118

Patent attorney

Spectro Cloud, inc

San Jose, CA · 95110

310-592-9499

Sophia R Petrichenko

Reg. 75998

Patent attorney

Knobbe, Martens, Olson & Bear, LLP

Irvine, CA · 92614

469-337-0510

Michael J Petrin

Reg. 50293

Patent attorney

Antero, Tormey & Petrin, PC

Pleasant Hill, CA · 94523

925-360-2361

David A. Petrini

Reg. 65868

Patent attorney

SunPower Corp.

San Jose, CA · 95134

408-457-2312

Anthony M. Petro

Reg. 59391

Patent attorney

Apple Inc.

Cupertino, CA · 95014

512-657-0440

Lena Petrovic

Reg. 72128

Patent agent

Union City, CA · 94587

510-517-4228

Douglas Allan Petry

Reg. 35321

Patent agent

San Ramon, CA · 94583

925-803-0706

Alexandria V. Petterson

Reg. 76140

Patent attorney

Apple Inc.

Cupertino, CA · 95014

408-340-8175

John P Pettit

Reg. 68619

Patent attorney

RPX

San Francisco, CA · 94111

415-852-3195

Benjamin H. Pezzner

Reg. 70711

Patent attorney

Morgan, Lewis & Bockius LLP

Palo Alto, CA · 94304

650-843-4000

Tavia V Pezzner

Reg. 74586

Patent attorney

Qualcomm Technologies, Inc.

San Jose, CA · 95110

408-533-9613

John Y Pfeifer

Reg. 52120

Patent attorney

KLA Tencor

Milpitas, CA · 95035

408-875-3000

Taylor E. Pfeifer

Reg. 77886

Patent attorney

Nixon Peabody LLP

Los Angeles, CA · 90071-3151

213-629-6000

Gloria Pfister

Reg. 45642

Patent agent

Edison Pharmaceuticals, Inc.

San Jose, CA · 95138

408-960-2194

Bach D. Pham

Reg. 81266

Patent attorney

Irvine, CA · 92618

949-414-6830

Hai-Chau D Pham

Reg. 54373

Patent agent

Milpitas, CA · 95035

408-262-7702

Matthew T. Pham

Reg. 83743

Patent attorney

Friedland Cianfrani LLP

Irvine, CA · 92614

217-991-0969

Tam Thanh Thi Pham

Reg. 50565

Patent attorney

Polsinelli LLP

San Francisco, CA · 94111

415-248-2116

Tim Hoang Pham

Reg. 48589

Patent attorney

Twitter, Inc.

San Francisco, CA · 94103

Vinh Huy Pham

Reg. 60053

Patent attorney

San Jose, CA · 95121

408-982-6101

Brigitte C Phan

Reg. 61941

Patent agent

Allergan, Inc.

Irvine, CA · 92612

714-246-3776

Terence Phan

Reg. 70923

Patent attorney

Law Offices of Ann Marie DeFelice

Rancho Cordova, CA · 95670

916-635-9965

Patrick Poupi Phancao

Reg. 50690

Patent attorney

Fountain Valley, CA · 92708

714-964-7961

Andrew A. Pharar

Reg. 75770

Patent attorney

Pharar Patents & Intellectual Property

Diamond Bar, CA · 91765

909-979-7287

Merene Philip

Reg. 75592

Patent agent

Therabody, Inc.

Los Angeles, CA · 90025

424-500-4150

Amethyst E. Phillips

Reg. 83859

Patent attorney

Goodwin Procter LLP

Los Angeles, CA · 90017

213-426-2500

John C. Phillips

Reg. 35322

Patent attorney

Fish & Richardson P.C.

San Diego, CA · 92130

858-678-5070

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.