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Philip S. Olsen

phone: 617-589-3826
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JD, Suffolk University Law School, 1982

BA, Stonehill College, 1979


Phil is a tax attorney focusing on state and local tax consulting and litigation. He has over 25 years’ experience litigating and resolving major tax controversies before courts and administrative boards. While he has a successful track record of litigating cases, he has also successfully and discretely resolved hundreds of cases short of trial. His experience spans just about every area of state and local tax, including corporate income, sales and use, personal income, estate, real and personal property, and unclaimed property. In addition to advocating for taxpayers on state level taxes, Phil represents property owners and municipalities in local property tax appeals.

Before entering private practice, Phil served as a senior trial attorney and litigation supervisor for the Massachusetts Department of Revenue where he represented the Department in many landmark tax cases. This experience gives him an insider perspective of the issues his clients face.

  • Reduced a $30+ million sales and use tax assessment against a national investment company to a nominal amount by demonstrating that the Department of Revenue’s sampling methodology was flawed.
  • Convinced Department of Revenue auditors that several major entertainment corporations were not unitary with each other and, therefore, not required to participate in a combined filing.
  • Successfully represented numerous high-net-worth individuals who changed their domicile from Massachusetts to other states.
  • Defended a national pharmaceutical company against income, sales and property tax assessments.
  • Obtained a protective order in Massachusetts Superior Court prohibiting the Department of Revenue from obtaining confidential customer information of a national distributor.
  • Negotiated local property tax reductions for owners of commercial, industrial, energy and hospitality properties.


  • Best Lawyers in America©, 2017-2021


  • Massachusetts


  • Boston Bar Association (Past Co-Chair of State and Local Tax Committee and Tax Controversy Committee)
  • Massachusetts Bar Association (Past Member and Past Chair of State and Local Tax Committee)
  • International Lawyers Network

Speaking Engagements:

Phil is a frequent public speaker on state and local tax and litigation issues. He has addressed organizations such as the Council of State Taxation, Tax Executives Institute, Institute for Professionals in Taxation, Massachusetts Bar Association, Boston Bar Association, Massachusetts Continuing Legal Education and Massachusetts Society of Certified Public Accountants.


When Phil is out of the office, he enjoys spending time with his family, running and coaching youth baseball.  He is also a member of the Bentley University MST Tax Advisory Board.

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