William Zac

Duffy

Shareholder
500 N. Akard Street, Suite 4000
Dallas, TX 75201

Overview

Zac focuses his practice on brand protection and trademarks, intellectual property, software development and licensing, and data privacy. Before entering practice, he earned his undergraduate degree in Management Information Systems from the University of Oklahoma and spent several years as a technical resource at a software company serving banks and other financial institutions. That background allows him to provide valuable counsel on matters that involve software or another form of technology.

Zac’s primary practice focus includes:

  • Trademark protection and enforcement, including management of a portfolio of more than 700 active US and International trademarks. Zac files new trademark applications and regularly represents clients before the Trademark Trial and Appeal Board (TTAB).
  • Software and technology licensing and development agreements. In addition to negotiating agreements, Zac also serves as lead trial counsel in litigation over software development projects involving unpaid fees for services rendered or allegations that software deliverables were defective or not provided as warranted.
  • Cybersecurity and Data Privacy, including privacy policies and compliance with United State and international data privacy laws like the EU GDPR.
  • Litigation involving copyrights, patents, trademarks, and trade secrets.

Zac was recently appointed as a World Intellectual Property Organization (WIPO) Arbitrator under the Uniform Domain-Name Dispute Resolution Policy (UDRP), the process that decides trademark-based domain name disputes. He is also included on the WIPO Arbitration and Mediation Center’s panel of mediators. To request a mediation from Zac in a matter involving trademarks, software, or intellectual property, please email him and include “Mediation” in the subject matter of your email.

Education

Admissions

Achievements

  • Thomson Reuters – Texas Rising Stars (2011-2018)
  • Woodward/White, Inc. – Best Lawyers in America, Litigation – Intellectual Property (2025-2027); Best Lawyers in America, Litigation – Patent (2027)
  • Memberships

    World Intellectual Property Organization (UDRP Arbitrator, 2026-present; Panel of Mediators, 2026-present)

Overview

Zac focuses his practice on brand protection and trademarks, intellectual property, software development and licensing, and data privacy. Before entering practice, he earned his undergraduate degree in Management Information Systems from the University of Oklahoma and spent several years as a technical resource at a software company serving banks and other financial institutions. That background allows him to provide valuable counsel on matters that involve software or another form of technology.

Zac’s primary practice focus includes:

  • Trademark protection and enforcement, including management of a portfolio of more than 700 active US and International trademarks. Zac files new trademark applications and regularly represents clients before the Trademark Trial and Appeal Board (TTAB).
  • Software and technology licensing and development agreements. In addition to negotiating agreements, Zac also serves as lead trial counsel in litigation over software development projects involving unpaid fees for services rendered or allegations that software deliverables were defective or not provided as warranted.
  • Cybersecurity and Data Privacy, including privacy policies and compliance with United State and international data privacy laws like the EU GDPR.
  • Litigation involving copyrights, patents, trademarks, and trade secrets.

Zac was recently appointed as a World Intellectual Property Organization (WIPO) Arbitrator under the Uniform Domain-Name Dispute Resolution Policy (UDRP), the process that decides trademark-based domain name disputes. He is also included on the WIPO Arbitration and Mediation Center’s panel of mediators. To request a mediation from Zac in a matter involving trademarks, software, or intellectual property, please email him and include “Mediation” in the subject matter of your email.

Experience

  • Copyright, Patent + Trademarks

    Represented Seasons USA, a leading manufacturer of novelty holiday-related toys, costumes and decorations, in a series of copyright, patent and trademark

    [more]
  • Trademarks (Trademark Trial and Appeals Board)

    Represented a software services company in trademark opposition proceeding.

  • Software

    Represented a software development company in litigation over unpaid fees allegedly due to faulty or defective software deliverables.

[more]