On January 6, 2026, the team from Sales Tax Defense, a leading firm specializing in sales and use tax matters, joined Armanino. This strategic move enhances Armanino’s capabilities in multi-state compliance, audit defense and dispute resolution.

Sales Tax Defense, established in 2008, is recognized for its deep technical expertise and thorough understanding of tax law and administrative processes. The firm has guided businesses through complex sales and use tax requirements, including filing obligations and audit strategies. This specialized knowledge complements Armanino’s broader tax practice, strengthening its position as a comprehensive resource for clients with sophisticated needs.

“Joining Armanino allows us to bring our specialized experience to a broader range of clients, including larger enterprises that are increasingly facing complex multi-state challenges,” said Mark Stone, CPA, MST, managing partner of Sales Tax Defense. “Together, we can offer deeper resources and additional capabilities, while ensuring our clients and the CPAs that we work with, continue to benefit from the hands-on approach Sales Tax Defense is known for.”

The integration of Sales Tax Defense into Armanino comes at a time when multi-state sales and use tax compliance has grown increasingly complex following the 2018 U.S. Supreme Court Wayfair decision. Businesses now face heightened audit activity and expanded enforcement efforts across states, creating new challenges in determining tax obligations.

Sales Tax Defense has long focused on client education, hosting more than 50 seminars annually to help businesses understand nexus rules and proactive compliance strategies. By joining Armanino, the team will combine its educational mission with advanced tax technology, automation and data analytics, providing clients with greater visibility, accuracy and control over compliance operations.