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 McCabe & Ali, LLP, Haley Guiliano LLP, and HRL Laboratories, LLC.

Top cities in California

All practitioners in California

Emil J Ali

Reg. 77055

Patent attorney

McCabe & Ali, LLP

Cerritos, CA · 90703

877-633-4097

Firasat M Ali

Reg. 45715

Patent agent

Haley Guiliano LLP

San Jose, CA · 95113

669-213-1072

Wais M. Ali

Reg. 80945

Patent agent

Irvine, CA · 92606

562-547-0076

Tina Alikahi

Reg. 73826

Patent agent

Santa Clara, CA · 95051

408-504-8437

Leonard A Alkov

Reg. 30021

Patent attorney

Los Angeles, CA · 90049

310-471-2306

Christian W. Allan

Reg. 83842

Patent attorney

Encinitas, CA · 92024

760-215-5530

Daniel R Allemeier

Reg. 46515

Patent attorney

HRL Laboratories, LLC

Malibu, CA · 90265

310-317-5851

Byron L Allen

Reg. 73917

Patent attorney

Intel Corporation

Santa Clara, CA · 95054

650-417-8483

Dan G. Allen

Reg. 69827

Patent agent

Cupertino, CA · 95014

408-466-5285

Kenneth R Allen

Reg. 27301

Patent attorney

Kilpatrick Townsend & Stockton LLP (retired)

Palo Alto, CA · 94303-4536

650-494-8868

Owen K Allen

Reg. 71118

Patent attorney

San Francisco, CA · 94114

202-421-4520

Christopher B Allenby

Reg. 45906

Patent attorney

ORANGE, CA · 92868

408-306-2191

Janet M. Allendorph

Reg. 79783

Patent attorney

Knobbe, Martens, Olson & Bear, LLP

Irvine, CA · 92614

858-707-4000

Annette L Allert

Reg. 75885

Patent agent

Solana Beach, CA · 92075

760-710-7416

Stephen Henry Allhoff

Reg. 72373

Patent attorney

San Jose, CA · 95136

314-814-4302

Reem S. Allos

Reg. 74856

Patent attorney

Reem Allos

San Diego, CA · 92129

858-382-0110

Hasan Almashat

Reg. 79166

Patent attorney

K&L Gates LLP

Palo Alto, CA · 94304

650-798-2840

Pablo A. Almazan

Reg. 65148

Patent agent

Los Angeles, CA · 90034

310-409-5635

George B Almeida

Reg. 20696

Patent agent

San Mateo, CA · 94404

650-571-5995

Arlyn L Alonzo

Reg. 44502

Patent attorney

Alonzo & Associates

Redondo Beach, CA · 90277

310-291-6738

Eric B Alspaugh

Reg. 54783

Patent attorney

Law Offices of Eric B. Alspaugh

Aliso Viejo, CA · 92656-5301

619-322-4114

Jenny M Alsup

Reg. 74823

Patent agent

Foster City, CA · 94404

650-225-3382

Jordan Aaron Altabet

Reg. 56502

Patent attorney

San Diego, CA · 92122

858-228-1765

Kurosu R. Altaf

Reg. 81433

Patent agent

Palo Alto, CA · 94303

650-799-2519

Katharine L Altemus

Reg. 51396

Patent attorney

Agilent Technologies, Inc.

Santa Clara, CA · 95051

408-553-7085

Brett Gregory Alten

Reg. 42258

Patent attorney

Hewlett Packard Enterprise

Palo Alto, CA · 94304

408-916-6996

Daniel E Altman

Reg. 34115

Patent attorney

Knobbe Martens Olson and Bear, LLP

Irvine, CA · 92614

949-760-0404

John Valentino A Alumit

Reg. 62690

Patent attorney

ALUMIT IP

Glendale, CA · 91205-4917

818-244-4861

Celeste M. Alvarez

Reg. 79296

Patent agent

Cooley LLP

San Diego, CA · 92121

858-550-6000

Ciara Alvarez-Malo

Reg. 79071

Patent agent

Greenberg Traurig

Irvine, CA · 92612

310-985-1049

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.