The Firm
Our history
Founded in 2019
SUMERSON was created by its founding Partners after years leading tax departments at top-tier corporate law firms. Having observed a clear lack of truly specialized tax professionals on the market at that time, they decided to build something different: an independent, agile structure exclusively dedicated to tax law, combining the expertise and rigor of leading firms with the responsiveness of a boutique.
Expanded in 2024
Having accompanied numerous clients with UAE operations and individual relocations to the Emirates, it felt natural to take the next step. SUMERSON opened a UAE-based branch to support our clients, and new ones, in an even more operational way in this jurisdiction. This expansion reflects our firm's core flexibility and our commitment to being present where our clients need us most.
Our Values
Reliability
Every recommendation is grounded in thorough analysis and precise legal reasoning. Nothing is delivered without first challenging every aspect of the matter to its core.
Agility
A lean structure that adapts to your timeline and the complexity of your situation.
International Culture
All our practitioners have trained and practiced in leading French and Anglo-Saxon law firms with international reach.
Responsiveness
We ensure direct access to senior counsel. No layers, the founding partner is fully involved in your case from the begining to the end.
Our Network
SUMERSON is actively embedded in the international tax community, through professional associations, recognized publications, and a global network of practitioners trained at the world's leading institutions.
Professional Associations
- IBAInternational Bar Association
- IFAInternational Fiscal Association
- IACFInstitut des Avocats Conseils Fiscaux
- AIJAAssociation Internationale des Jeunes Avocats
- GEOGlobal Equity Organization
Publications & Networks
International Tax Review
Contributing author
Global Law Expert
Member network
ESCP Business School
Academic partner
Academic Connections
We work closely with practitioners who trained at New York University and Harvard Law School and now hold senior positions across the world, providing SUMERSON with privileged access to the most sophisticated international tax thinking and network.
Recognition
Advisory Excellence
International Tax Expert of the Year
United Arab Emirates — 2026
Nicolas Duboille was selected by the Advisory Excellence Awards Panel as the International Tax Expert of the Year in the United Arab Emirates for 2026.
Global Law Experts
Gold Member — International Tax
France
Nicolas Duboille holds a Gold designation from Global Law Experts for International Tax in France, a distinction awarded after independent vetting by practice area and jurisdiction.
Leaders League — Décideurs
Highly Recommended — Tax Law
France — 2021, 2025
SUMERSON is ranked "Forte notoriété" (Highly Recommended) by Leaders League in its Décideurs rankings of French law firms, in two tax categories: Taxation of International Groups and Transaction Tax.
Best Lawyers
The Best Lawyers in France — Tax Law
France — 2027 Edition
Nicolas Duboille is recognized in The Best Lawyers in France™ for Tax Law, a distinction based exclusively on peer review by leading lawyers in the same practice area.
Discover SUMERSON
Explore our firm presentation to learn more about our practice, expertise and international reach.
PDF — Firm Presentation
The Name “Sumerson”
SUMERSON takes its name from the Sumerians, the ancient civilization credited with the earliest written tax laws in human history. These laws were engraved on stone tablets known as Sumerstones. They represent the very first formalization of human tax policy thought.
The name reflects our philosophy. We believe that rigorous tax advice begins by going back to the origin of things, meaning returning to the foundational texts, questioning well-established conventions and examining the rationale behind each legal rule. Tax law is too often practised as a matter of engineering, applying ready-made structures and following the crowd. We take a different path. We think independently, question what others take for granted, and read the law for its meaning, not just its mechanics.
