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 Sun Microsystems, Inc., Stamps.com Inc., and Kubota & Basol LLP.

Top cities in California

All practitioners in California

Rick Weisberg

Reg. 43254

Patent attorney

Sun Microsystems, Inc.

Menlo Park, CA · 94025

650-786-6255

Seth David Weisberg

Reg. 44397

Patent attorney

Stamps.com Inc.

Los Angeles, CA · 90245

310-482-5808

Erika D. Weisdorfer

Reg. 83857

Patent attorney

Kubota & Basol LLP

Los Angeles, CA · 90017

858-952-2202

Joshua G Weisenfeld

Reg. 80496

Patent attorney

Sheppard Mullin

San Diego, CA · 92130

507-995-2247

Anatoly S Weiser

Reg. 43229

Patent attorney

San Diego, CA · 92130

858-720-9431

Marie A Weiskopf

Reg. 65284

Patent attorney

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.