My Profile

Mark Stone


Contact Details



Managing Partner

Mark Stone is the Managing Partner of Sales Tax Defense LLC since 2006. The firm specializes in Sales, Use and Transaction Taxes. Mark's work as a NY state tax auditor as well as a Tax Manager at several prominent accounting firms over the past 20 years has earned him a reputation as one of the top professionals for multi-state Sales and Use Taxes. He is frequently invited by various organizations to speak on Sales & Use Tax issues, and serves as an Expert witness testifying in tax court on behalf of clients. Mark is an adjunct professor at Long Island University C.W. Post.

Areas of Practice - Sales and Use Tax

• Multi-state Sales and Use Tax consulting
• Sales and Use Tax audit defense
• Sales and Use Tax refunds and recovery
• Complex sales tax planning and research
• Sales Tax Criminal Defense Assistance
• Representation before government revenue agencies and auditors
• Representation as expert witness in Sales and Use Tax court cases
• Advocating for clients at the Bureau of Conciliation and Mediation Services

Professional Affiliations:

New York State Society of Certified Public Accountants (NYSSCPA), Member
National Conference of CPA Practitioners (NCCPAP), Member
Accountant/Attorney Networking Group (AANG), Member
Network of Accountants (NOA), Member
Turnaround Management Association (TMA), Member
American Institute of Certified Public Accountants (AICPA), Past Member

Publication Credits:

Published columns in various media including Long Island Business News, Beyond the Numbers, Private Investment Forum, New York State Society of CPAs Nassau Chapter Newsletter, Daily News, Long Island Pulse Magazine, Nassau Lawyer

Quoted in various media including Crain's New York Business and Practical Accountant

Speaking Credits:

New York State Society CPA (NYSSCPA) Nassau Chapter, Half-Day State and Local Tax Update
Nassau Bar Association
Suffolk Bar Association
Chambers of Commerce
National Conference of CPA Practitioners (NCCPAP)
Network of Accountants (NOA)
New York State Independent Accountants (NYSIA)
New York Sales and Use Tax for Manufacturers program, Faculty (NBI)
The Tax Institute at Long Island University (C.W. Post), Moderator and Speaker
Key Speaker, Nassau & Suffolk Chapters Half-Day Federal & State Taxation Conferences
Sales Tax Seminars for Accounting Firms & Law Firms


Masters degree in Taxation (with Honors), C.W. Post, Long Island University 2003
Bachelor of Science in Accounting and Information Systems, City University of New York 1992