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 Knobbe Martens Olson and Bear LLP, ALC Patent Solutions, and Tressler, LLP.

Top cities in California

All practitioners in California

Jason A. Champion

Reg. 68316

Patent attorney

Knobbe Martens Olson and Bear LLP

Irvine, CA · 92614

949-760-0404

Allen L. Chan

Reg. 78564

Patent agent

ALC Patent Solutions

Milpitas, CA · 95035

408-613-9007

Andrew J. Chan

Reg. 68317

Patent attorney

Tressler, LLP

Walnut Creek, CA · 94597

925-332-0440

Andy H Chan

Reg. 56893

Patent attorney

Infineon Technologies

San Jose, CA · 95134

669-308-7995

Christine W Y Chan

Reg. 66982

Patent agent

Menlo Park, CA · 94025

650-799-9693

Darby J. Chan

Reg. 62407

Patent attorney

Foley & Lardner LLP

San Francisco, CA · 94105

415-434-4484

David H Chan

Reg. 51540

Patent attorney

Western Digital Technologies, Inc.

Irvine, CA · 92612

949-672-7365

Eric D. Chan

Reg. 60750

Patent agent

O'Melveny & Myers, LLP

Los Angeles, CA · 90071

213-430-6000

Gerald Chan

Reg. 51541

Patent attorney

Vista IP Law Group , LLP

San Jose, CA · 95131

510-329-1009

Jason W Chan

Reg. 84849

Patent attorney

Del Mar, CA · 92014

202-417-7555

Joan Y Chan

Reg. 66385

Patent attorney

Knobbe, Martens, Olson & Bear, LLP

Irvine, CA · 92614

949-760-0404

Konrad K. Chan

Reg. 57857

Patent attorney

Medtronic Diabetes

Northridge, CA · 91325-1219

818-576-4330

Kwan Chan

Reg. 52714

Patent agent

Fenwick & West

Mountain View, CA · 94041

650-335-7124

May Y Chan

Reg. 51053

Patent attorney

Waymaker LLP

Los Angeles, CA · 90071

424-335-2404

Melvin D Chan

Reg. 39626

Patent attorney

Aka Chan LLP

Santa Clara, CA · 95050

408-800-1912

Ming Fai Chan

Reg. 56096

Patent agent

Encinitas, CA · 92024

760-632-8726

Ngam Fung David Chan

Reg. 76820

Patent attorney

Instil Bio Inc.

Thousand Oaks, CA · 91320

714-721-8652

Perry S Chan

Reg. 68752

Patent attorney

Law Office of Perry Chan

Woodland Hills, CA · 91367

818-674-6983

Raymond Yat Chan

Reg. 37484

Patent agent

Monterey Park, CA · 91754

626-571-9812

Raymond K Chan

Reg. 66164

Patent attorney

Netlist, Inc.

Irvine, CA · 92617

949-679-0101

Rita S Chan

Reg. 55047

Patent attorney

Santa Clara Valley Water District

San Jose, CA · 95118

408-265-2600

Stephanie A Chan

Reg. 65302

Patent agent

San Francisco, CA · 94132

415-681-8209

Ted W Chan

Reg. 43536

Patent attorney

San Jose, CA · 95140

408-926-9692

Ted Alfred Chan

Reg. 46609

Patent attorney

Allergan, Inc.

Irvine, CA · 92612-1599

714-246-2918

Thomas C Chan

Reg. 51543

Patent attorney

Silicon Valley Patent Group LLP

San Jose, CA · 95117

408-378-7777

Tony Chan

Reg. 77619

Patent agent

M&H, LLP

Menlo Park, CA · 94025

650-331-7008

Katy K Chan-Parsons

Reg. 71775

Patent agent

The Walt Disney Company

Burbank, CA · 91521

929-618-7923

Janet D Chance

Reg. 55048

Patent agent

Kokka & Hsu, PC

Mountain View, CA · 94043

650-428-0312

Paul D Chancellor

Reg. 52715

Patent attorney

Ocean Law

Simi Valley, CA · 93063

805-368-4586

Wayne M Chancellor

Reg. 51249

Patent attorney

Composite Optics INC

San Diego, CA · 92121

858-621-6956

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.