Loopholes in international tax legislation contribute to the misuse of tax rules by multinationals. Leiden University legal experts investigate how the complex national and international tax rules can be made more consistent in order to create a better tax system.

Assessing the feasibility and legitimacy of the current model of global tax governance and the role of the OECD and EU in international tax law-making.

The study of tax law covers the tax system in its full width. It includes domestic, international and European tax law.

On 12 and 13 September 2019, the Institute of Tax Law and Economics from Leiden University hosted 29 PhD researchers from around the world to engage into collective discussions at the Multilateral Cooperation in International Tax Law seminar.

The Institute of Tax Law and Economics at Leiden Law School has three departments: the Department of Tax Law, the Department of Economics and the Department of Business Studies. The Institute brings together research and teaching at the point at which, on the one hand, law and, on the other, fiscal…

The master’s programme 'Fiscaal Recht' provides you with in-depth theoretical and practical knowledge on all the ins and outs of tax law.

Do you like solving complex legal puzzles? Do you like analysing problems? If so, the bachelor’s programme Fiscaal Recht is right for you.

Courses EU Tax Governance (EUTAXGOV).

On Thursday 16 November, Dirk Broekhuijsen defended his doctoral thesis entitled ‘A multilateral tax treaty: designing an instrument to modernise international tax law’. The supervisors are Professor F.A. Engelen and Professor S.C.W. Douma.

Tax scandals, like the Panama Papers, the Paradise Papers, and the Pandora Papers, have made taxation a major topic of public debate. Learn more about this in the new minor Tax and Society: Building a Sustainable and Fair Tax System.

In the past few years, an increasing number of multinationals have made the news for large-scale use of tax planning opportunities. The Organisation for Economic Collaboration and Development (OECD) and the European Commission are studying these cases closely and investigating whether the current concepts…

On Thursday 1 December 2016 at 13.45 hrs, Francisco Sepulveda Ramirez will defend his doctoral thesis ‘Residence in Tax Treaties' at the Academy Building of Leiden University. Supervisor is Professor F.A. Engelen.

Researchers from the Department of Tax Law were lead authors of a report on corporate taxation and digitalization for the World Economic Forum.

Multinationals use loopholes in the tax treaties between different states. A possible solution would be to eliminate all these loopholes in one go by creating a central global treaty. Leiden researchers are investigating whether this kind of mega-treaty is feasible.

How do tax treaties have to be explained and implemented, and what role does the supranational regulatory process play in this? Which objectives are meant to be used in establishing tax regulations and to what extent are such legislative practices undertaken in a goal-oriented manner?.

The Panama Papers and Paradise Papers provide evidence that companies and individuals are evading tax on a large scale. Worldwide tax agreements can put a stop to this. But for the time being a treaty that will address the problem at its root is not in sight, in the opinion of legal expert Dirk Broekhuijsen.…

Complex systems can be characterized as systems in which multiple components interact with each other, often in non-linear ways. The main goal of this research will be to investigate if and how the international tax system can be defined and modelled as a complex system. Approaching the international…

In this PhD-thesis several new and existing data science application are described that are particularly focused on applications for tax administrations.

Tech company Uber uses various tricks via the Netherlands to avoid paying tax on its profits. A $16 billion inter-company loan from Singapore has prompted questions with experts claiming the loan is not under arm’s length terms. MEP Paul Tang wants Brussels to investigate.

If the Netherlands wants to change its reputation as a tax haven, it must do more according to Professor of Tax Law Jan van de Streek on American news site Bloomberg.

The EUTAXGOV Chair will address the EU Standard of Tax Good Governance. This Standard has been introduced in 2008 by the ECOFIN Council with a view to tackle tax fraud and evasion by companies and individuals and as a pre-condition for third (non-EU) countries that receive EU development aid, and concluded…

We would all like to live in a world in which individuals feel safe, conflicts are resolved peacefully and the interests of future generations are taken into consideration. At Leiden University legal scholars investigate to what extent public international law meets the needs of a globalised society.…

On 22 February, Elody Hutten defended the thesis 'Tax Professionals Under Societal Pressure: A Dutch Case Study on Responses to BEPS'. The doctoral research was supervised by Henk Vording en Jan Vleggeert.

Before he became Minister of Finance, CDA leader Wopke Hoekstra invested for years in a shell company in the Virgin Islands. This has been revealed in leaked documents known as the Pandora Papers. How exactly does tax avoidance work? And are there other options? Tax lawyers Jan Vleggeert and Tanja…

On 15 March 2023, the GLOBTAXGOV team at Leiden Law School met with the Inter-American Center of Tax Administrations (CIAT) to explore opportunities for cooperation, to discuss the needs of tax administrations in the field of international taxation and evaluate ongoing projects and new initiatives where…

Jan Vleggeert is a tax specialist with an independent and critical voice in the debate on tax avoidance by multinationals. His appointment commenced on 1 October 2019.

Professor Sjoerd Douma has been named the top lecturer on Coursera, the best-known platform for online courses. Students gave him an average score of 9.8 - almost unheard of for a lecturer in International Tax Law.

Amy Strecker assesses the institutional framework for landscape protection, analyses the interplay between landscape and human rights, and links the etymology and theory of landscape with its articulation in law.

On Friday 17 November 2017, H.E. Dr. María Fernanda Espinosa, Minister of Foreign Affairs and Human Mobility of the Republic of Ecuador gave a lecture on Fairness in Global Taxation at the Grotius Centre for International Legal Studies at Leiden University, Campus The Hague.

On 12 March, Frederik Heitmüller defended the thesis 'Combatting tax avoidance, the OECD way? The impact of the BEPS Project on developing and emerging countries’ approach to international tax avoidance'. The doctoral research was supervised by Madeleine Hosli and Irma Mosquera Valderrama.

On 10 October 2018, Richard Resch defended his doctoral thesis 'The Interpretation of Plurilingual Tax Treaties'. The doctoral research was supervised by Prof. mr. C. van Raad.

On the occasion of Euroscience Open Forum 2022, Professor Attiya Waris (Director of Research and Enterprise and Professor of Fiscal Law and Policy in Eastern Africa, University of Nairobi, Kenya), Professor Irma Mosquera Valderrama (Professor of Global Tax Governance, Lead Researcher GLOBTAXGOV ERC…