Nicolas Duboille is a renowned tax lawyer with more than 20 years of professional experience. He has sought-after expertise, particularly in the fields of international taxation, taxation of investment funds and asset management, property taxation and taxation of the natural resources sector.

He has developed expertise in tax law applied to transactions on crypto-assets, Defi start-ups and NFT market platform.

He works for a diversified clientele, made up of French and foreign companies, investment funds and management companies, financial institutions and individuals.

He also works as an expert with States, local authorities and NGOs.
He is regularly ranked by professional guides among the best French tax experts.

Nicolas Duboille is a lawyer at the Bars of Paris (CAPA 1999) and New York (New York State Bar Exam 2006).


Before founding Sumerson with part of the team he led at Simmons & Simmons, Nicolas Duboille practiced in the following firms:

  • Deloitte & Touche JF (later Taj)
  • Jones Day
  • Lovells (now Hogan Lovells)
  • Latournerie Wolfrom (where he created and directed the tax practice)
  • Granrut (in which he was a partner for 7 years, in charge of the firm's tax practice)
  • Simmons & Simmons (where he was Partner, Head of Tax)


Comparative Tax and Administration Program, Harvard University, Harvard Kennedy School of Government 

LLM in International Taxation, New York University School of Law (training ranked n°1 in international taxation in the USA and worldwide) 

Cycle of Advanced Studies for Economic Development, Institute of Public Management and Economic Development (IGPDE)

Bar Training School of the Court of Appeal of Paris (EFB) 

DESS in Business Law, DEA in Public Finance and Taxation (University of Paris II Panthéon-Assas)


Nicolas Duboille regularly teaches corporate taxation and international taxation at ESCP Europe (Grande Ecole course), in French and English, as well as within the framework of specialized Masters and DJCE.

He also occasionally works as a trainer for professional training organizations such as Comundi.

Nicolas is a member of the prestigious NYU School of Law International Practice Council, bringing together world experts in international taxation.


Member of the International Fiscal Association (IFA), the Institute of Tax Lawyers (IACF), the International Association of Young Lawyers (AIJA), the Global Equity Organization (GEO).


Nicolas Duboille is a frequent speaker at conferences or seminars on the topics of French and international taxation, or tax policy.

He regularly publishes articles or studies in the field of tax law. For example, he is the author of the French part of the IBFD guide on the Taxation of Investment Funds.