William J. Kambas

Partner | Greenwich, New Haven, New York

Bill is a partner in the private client and tax team.

He focuses on tax planning for multi-national and multi-state personal, active business, and investment activities, with a particular emphasis on tax structuring and choice of business entity for US and non-US business owners and investors.

Bill has represented a wide variety of private and public businesses, including family-owned, start-ups and multi-million dollar enterprises on purely domestic as well as inbound and outbound business transactions, cross-border investments (whether made directly or through investment funds or joint ventures), and qualification for US tax treaty benefits. In particular, he has considerable experience advising non-US persons on the US income and estate tax consequences and tax planning associated with the ownership of US real estate (whether residential or commercial, developmental, operational, or for personal use). Bill spoke to Family Capital about the challenges that the new US tax legislation poses to single family offices

An integral part of Bill’s work involves working assisting families, their family offices, and/or family enterprises with the formation, management, and/or periodic evaluation of multinational and/or multi-generational centralized control and management structures.

In addition to numerous speaking engagements, organization memberships and publications, Bill has also been featured as a guest lecturer at the Hellenic Studies Program at Yale University, the Columbia Business School at Columbia University, the University of Connecticut School of Law and the Charles F. Dolan School of Business at Fairfield University.

Secretary Mary Marshall





State of Connecticut, 2003

State of New York, 2004

United States Tax Court, 2004

‘The "new" alternative minimum tax,’”:“https://www.withersworldwide.com/en-gb/the-new-alternative-minimum-tax Withers article - February 13, 2018, co-author”“:https://www.withersworldwide.com/en-gb/single-family-office-operations-2018-recent-case-law-and-coordination-with-legislative-developments

Skidmore College Annual Fund, President

Saint Barbara Greek Orthodox Church Endowment Fund, Chairman

International Fiscal Association (Westchester, NY and Connecticut Region), Executive Committee

‘5th Annual Family Business School Conference_-_Family Office Panel,’ Columbia Business School - February 9, 2018, moderator

‘US Tax Reform,’ STEP Canada/STEP USA Webcast - January 19, 2018, panelist

‘Interactive round table discussion’, STEP International Estate Planning Conference Wyoming - September 15-16, 2017, moderator



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Suite 400,

CT 06870-1366

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New Haven

157 Church Street,

CT 06510-2100

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New York

430 Park Avenue,

10th Floor,

NY 10022-3505

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