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 Law Office of Ernst Halperin, Latham & Watkins LLP, and K&L Gates LLP.

Top cities in California

All practitioners in California

Ernst A Halperin

Reg. 55241

Patent attorney

Law Office of Ernst Halperin

San Francisco, CA · 94104

415-494-7327

Nancy S Halpin

Reg. 57087

Patent attorney

Latham & Watkins LLP

Menlo Park, CA · 94025

650-463-2627

Erik James Halverson

Reg. 73552

Patent attorney

K&L Gates LLP

San Francisco, CA · 94111

415-882-8238

Nicholas E Ham

Reg. 68706

Patent attorney

Sunnyvale, CA · 94085

951-326-9795

Thomas H Ham

Reg. 43654

Patent attorney

Loza & Loza, LLP

Upland, CA · 91786

877-406-5134

Maha A Hamdan

Reg. 43655

Patent attorney

Medlen & Carroll, LLP

Oakland, CA · 94612

510-788-8781

Joel A. Hamel

Reg. 75758

Patent attorney

Dentons US LLP

Palo Alto, CA · 94304

Charles L Hamilton

Reg. 42624

Patent attorney

Fountainhead Law Group, PC

Campbell, CA · 95008

408-244-6319

Drew S Hamilton

Reg. 29801

Patent attorney

Poway, CA · 92064

619-890-8630

Jennifer H. Hamilton

Reg. 41814

Patent attorney

The Eclipse Group LLP

Granada Hills, CA · 91344

818-488-8141

Joseph P Hamilton

Reg. 51770

Patent attorney

Perkins Coie LLP

Los Angeles, CA · 90067-1721

310-788-9900

Kevin C. Hamilton

Reg. 67593

Patent attorney

DLA Piper LLP (US)

San Diego, CA · 92101

619-804-4701

Marianna Hamilton

Reg. 38905

Patent attorney

Escondido, CA · 92025

760-822-1474

Robert S Hamilton

Reg. 56101

Patent attorney

Cisco System, Inc.

San Jose, CA · 95134-1706

408-526-4000

Daniel T Hamling

Reg. 71466

Patent agent

Oceanside, CA · 92056

858-692-1343

Michael S Hammer

Reg. 38483

Patent attorney

Waste Management

Sun Valley, CA · 91352

818-252-3148

Alan Wayne Hammond

Reg. 35178

Patent agent

Carlsbad, CA · 92008

760-481-4874

John B Hammond

Reg. 36820

Patent attorney

Hammond Law Office

San Diego, CA · 92130

858-794-0012

Krishna R Hammond

Reg. 80510

Patent attorney

USD Legal Clinics

San Diego, CA · 92110

619-361-1187

Mark D Hammond

Reg. 75822

Patent agent

Mintz, Levin, Cohn, Ferris, Glovsky and Popeo P.C.

San Diego, CA · 92130

858-314-1086

Stephen M Hamon

Reg. 67228

Patent attorney

Stetina Brunda Garred & Brucker

Aliso Viejo, CA · 92656

949-855-1246

Claude A S Hamrick

Reg. 22586

Patent attorney

Hamrick IP Law Office

Lincoln, CA · 95648

916-587-1780

Michelle A Hamson

Reg. 81396

Patent attorney

Dinsmore & Shohl

San Diego, CA · 92101

619-400-0483

Ada P Han

Reg. 55243

Patent agent

Sunnyvale, CA · 94087

408-314-8916

Daniel C Han

Reg. 66138

Patent attorney

Santa Clara, CA · 95054

408-512-1907

EunHee Han

Reg. 74578

Patent attorney

Wilson Sonsini Goodrich & Rosati

San Diego, CA · 92130

323-210-2908

Franklin Y Han

Reg. 41055

Patent attorney

Patent Law Works LLP

San Jose, CA · 95131

650-537-4500

Hyun Kyu C. Han

Reg. 71958

Patent attorney

Morrison & Foerster LLP

Palo Alto, CA · 94304-1018

650-813-4043

John C Han

Reg. 41403

Patent attorney

Qualcomm Inc

San Diego, CA · 92121

858-845-7255

Johney U Han

Reg. 45565

Patent attorney

Levine Bagade Han LLP

Palo Alto, CA · 94303

650-242-4217

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.