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 Abbott Laboratories, Nixon Peabody LLP, and Wilson Sonsini Goodrich & Rosati, PC.

Top cities in California

All practitioners in California

Shannon M Hansen

Reg. 46004

Patent attorney

Abbott Laboratories

Alameda, CA · 94502

510-749-5011

Shawn G Hansen

Reg. 42627

Patent attorney

Nixon Peabody LLP

Los Angeles, CA · 90071

213-629-6190

Stephen C Hansen

Reg. 35180

Patent agent

Oak Park, CA · 91377

818-889-2783

Kristina M. Hanson

Reg. 74663

Patent attorney

Wilson Sonsini Goodrich & Rosati, PC

San Francisco, CA · 94105

415-947-2000

Thomas C Hanson

Reg. 80912

Patent agent

Oakland, CA · 94619

646-504-5808

Carlos Luis Hanze

Reg. 43657

Patent attorney

Danville, CA · 94506

925-856-0455

James Ping-Yi Hao

Reg. 36398

Patent attorney

Murabito, Hao & Barnes

San Jose, CA · 95113

408-938-9060

Joe C Hao

Reg. 55246

Patent attorney

KILPATRICK TOWNSEND & STOCKTON, LLP

Walnut Creek, CA · 94596

925-472-5000

Rita A Hao

Reg. 51775

Patent attorney

University of California, Office of the General Counsel

Oakland, CA · 94607

510-987-9734

Azir U Haque

Reg. 45859

Patent attorney

Phillips Electronics

San Jose, CA · 95131

408-904-3619

Marwan A Harara

Reg. 51776

Patent attorney

The Regents Of The Univ Of California

Oakland, CA · 94607

510-587-6000

Danica T. Harbaugh

Reg. 83121

Patent agent

Ashurst Perkins Coie US LLP

Palo Alto, CA · 94304

650-838-4505

Michael R Hardaway

Reg. 52992

Patent attorney

Springville, CA · 93265

408-410-5659

Ian Hardcastle

Reg. 34075

Patent attorney

None

Aptos, CA · 95003-4521

408-455-1211

Jonathan H. Harder

Reg. 75301

Patent attorney

Dickinson Wright RLLP

Sunnyvale, CA · 94086

512-770-4218

Jason Eric Hardiman

Reg. 36157

Patent attorney

Intuit Inc.

Mountainview, CA · 94043

630-944-3641

David Hardoon

Reg. 64342

Patent attorney

David Hardoon

San Diego, CA · 92103

949-822-8222

Kristal M. Hardoon

Reg. 69277

Patent attorney

San Diego, CA · 92128

615-513-0367

Ingo H Hardt

Reg. 54152

Patent attorney

Wilson Sonsini Goodrich & Rosati

San Diego, CA · 92130

858-350-2352

Zachary J. Hardy

Reg. 83393

Patent attorney

Jones Day

Palo Alto, CA · 94303

650-739-3939

Bruce A. Hare

Reg. 58968

Patent attorney

Genius Patent APC

San Diego, CA · 92106

619-880-9464

Joseph C. Harkins

Reg. 78161

Patent attorney

Joseph C. Harkins Esq

San Diego, CA · 92102

858-565-4585

Joan C Harland

Reg. 51779

Patent agent

Oakland, CA · 94611

510-338-0548

Susan L Harlocker

Reg. 59144

Patent agent

Genentech, Inc

South San Francisco, CA · 94080

650-303-6934

Donn K Harms

Reg. 38911

Patent attorney

American Patent and Trademark Law Center Inc.

Del Mar, CA · 92014

858-509-1400

Albert J Harnois· Jr

Reg. 46123

Patent attorney

Cavium, INC

San Jose, CA · 95131

408-943-7641

Rosalio Haro

Reg. 42633

Patent agent

Epson Research and Development, Inc.

San Jose, CA · 95131

408-952-6131

Victor M Haroldsen

Reg. 70295

Patent agent

West Sacramento, CA · 95691

530-902-3008

Sohrab Haroonian

Reg. 50950

Patent attorney

Sohrab Haroonian

Van Nuys, CA · 91401

818-785-6733

Burch A Harper

Reg. 42635

Patent attorney

Kateeva, Inc.

Newark, CA · 94560

800-385-7802

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.