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Dr B. (Blazej) Kuzniacki

Faculty of Law
Tax Law

Visiting address
  • Nieuwe Achtergracht 166
Postal address
  • Postbus 15557
    1001 NB Amsterdam
Contact details
  • Profile

    Błażej Kuźniacki is an Assistant Professor at the University of Amsterdam in the field of Tax and Technology with a special focus on artificial intelligence (AI) technologies and direct taxation. As a member of the Amsterdam Centre for Tax Law (ACTL), Błażej is one of the academic leaders (Tax & Technology) of the UvA’s research project "Designing the tax system for a Cashless, Platform-based and Technology-driven society" (CPT project) together with Prof. Dr. Evangelos Kanoulas from the Informatics Institute, Faculty of Science at the UvA. A focal point of his research at the CPT is currently explainable artificial intelligence (XAI)  in tax law. Kuzniacki’s research efforts contribute to addressing a key and fundamental question: how to ensure that AI tools deployed in the field of taxation are trustworthy and beneficial to all stakeholders (i.e. taxpayrs, tax authorities and courts)? Ensuring the explainability, accuracy and fairness of decisions made on the basis of AI models is central to the acceptance and future adoption of these technologies in all domains and specially in taxation.

    Błażej has a Ph.D. in Tax Law (University of Oslo, Norway) and two Master of Arts degrees in Law and European Studies (Nicolaus Copernicus University in Torun, Poland). Błażej is also a tax practitioner (currently: PwC) and attorney-at-law admitted to the Polish Bar, with a focus on strategic tax advice, cross-sections of international tax and investment law, and interdisciplinary interrelations between AI technologies and taxation. He completed a full time post-doctoral research fellowship at the Singapore Management University (2017-2018) and a full time PhD research program at the Department of Public and International Law at the University of Oslo (2012-2016). He is a member of the International Fiscal Association (IFA) and a member of the International Association for Artificial Intelligence and Law (IAAIL).

    Kuźniacki is the author of around 100 publications with national and global coverage. His doctoral thesis “Controlled Foreign Companies (CFC) and Tax Avoidance” was published by C.H. Beck and critically acclaimed in the Intertax Literature Review by Professor Brian Arnold. The thesis was prepared under the supervision of Prof. Dr. Frederik Zimmer (University of Oslo) and defened before the Adjudicating Committee which was composed of Prof. Dr. Arvid Aage Skaar (University of Oslo), Dr. Bettina Banoun (Wiersholm) and Dr. hab. Adam Zalasiński (European Commission).

    Kuźniacki is also a guest lecturer at various universities worldwide. For the outcomes of his scientific work, he was awarded, among other things, the 2015 Scholarship of Foundation for Polish Science, the 2014 Honourable mention and the 2016 IFA President YIN Scientific Award, and the 2021-2023 Scholarship for Outstanding Young Scientists in Poland. His scientific works and legal opinions on tax matters, particularly in the area of international and EU tax law, have been quoted, among the others, by the Supreme Administrative Court in Poland in many high-profile tax cases.

  • Representative publications

    Articles (single authored)

    • X-GmbH v Finanzamt Stuttgart — Körperschaften: The Evolution of the EU Standard of Abuse of Tax Law and the Role of the Genuine Exchange of Tax Information between Member States and Third Countries, Modern Law Review (21 July 2021) (available online at:
    • Poland’s Implementation of EU GAAR Compromises Constitutional and EU Principles, Intertax 3/2021 (available online at:
    • Converging Global Standard of General Anti-Abuse Rule:  GAAR (ATAD) and PPT (MLI), Centre for Analyses and Studies of Taxation 1/2020 (available online at:
    •  The C.J.E.U. Case Law Relevant to the General Anti-Avoidance Rule (G.A.A.R.) Under the Anti-Tax Avoidance Directive (A.T.A.D.), University of Bologna Law Review 2/2019 (available online at:
    •  The ECJ as a Protector of Tax Optimization via Holding Companies, Intertax 3/2019
    • The Artificial Intelligence Tax Treaty Assistant: Decoding the Principal Purpose Test, Bulletin for International Taxation 9/2018.
    • The Principal Purpose Test (PPT) in BEPS Action 6/MLI: Exploring Challenges arising from its Legal Implementation and Practical Application, World Tax Journal 2/2018
    •  Singapore’s Introduction of the Principal Purposes Tests (PPT) and Discretionary Benefits Provisions to its Tax Treaties: Not as Black as it is Painted (Part 1 – Reasons and Part 2 – Consequences), Asia Pacific Tax Bulletin 2/3 & 3/4 /2018
    • (In)Compatibility of the Polish CFC Rules with the Constitution before and after the Implementation of ATAD, European Taxation 4/2018
    • Implementing the ATAD’s CFC rules by Poland Contrary to EU Primary Law:  A Solitary Example or the Beginning of Infamous Trend?, EC Tax Review 3/2018
    • Constitutional Issues arising from the Principal Purposes Test: The Lesson from Poland, Studia Iuridica Lublinensia 4/2018 (available online at:
    • The Limitation on Benefits Provision in BEPS Action 6/Multilateral Instrument: Ineffective Overreaction of Mind-Numbing Complexity – Part 1 and Part 2, Intertax 2/3/2018
    • Discretionary Benefits Provisions under the MLI – A Vicious or Virtuous Circle?, Tax Notes International (31 July 2017)
    • Tax Avoidance through Controlled Foreign Companies under European Union Law with Specific Reference to Poland, in Accounting, Economics, and Law: A Convivium (AEL), Founding Editors: R. S. Avi–Yonah, Y. Biondi, and S. Sunder, (available online at:
    • Preventing Tax arbitrage via Hybrid Mismatches: BEPS Action 2 and Developing Countries, WU International Taxation Research Paper Series, No. 2017 – 03, (available online at:
    • Norway’s Recent Efforts to Prevent International Tax Avoidance, Tax Notes International (29 February 2016)
    • The need to avoid double economic taxation triggered by CFC rules under tax treaties, and the way to achieve it, Intertax 12/2015
    • CFC Rules, BEPS Action 3 (Draft), and EU Law, WU International Taxation Research Paper Series via SSRN, (available online at:
    • Unequal tax treatment of CFCs towards domestic partnerships, economic double taxation, exchange of tax information and future developments of the Norwegian CFC rules, Skatterett 4/2014
    •  EEA exemption from Norwegian CFC rules, Skatterett 3/2014
    •  Tax treaty exemption from Norwegian CFC rules, Skatterett 2/2014
    • The Service PE Concept in Light of the Poland–Norway Income Tax Treaty (2009), European Taxation 1/2014
    •  Tax Treaty Interpretation by Supreme Courts: Case Study of CFC rules, in International Tax Principles in BRICS and OECD Countries: Divergences and Convergences, Brazilian Institute of Tax Law (IBDT) in São Paulo (available online at:
    •  Sustainable Development in Poland and Anti–Avoidance Provisions: the Rationale for Introducing CFC Rules into the Polish Tax Law System, in Social and Environmental Dimension of Sustainable Development: Alternative Models in Central and Eastern Europe, Collection of papers from the 6th Forum of PhD Students International Seminar at the European Parliament, Brussels, October 15–17, 2012, Friedrich Ebert Stiftung

    Articles (co-authored)

    • Reasoning with and about Factors in Statutory Interpretation, Proceedings of the 4th International Workshop on Mining and Reasoning with Legal texts co-located with the 32nd International Conference on Legal Knowledge and Information Systems (JURIX 2019) , co-written with M. Araszkiewicz and T. Żurek, (2019),  (available online at:
    • Toward Frictionless Trade and Frictionless Compliance: The Challenges and Opportunities of Blockchain, Tax Notes International (14 May 2018), co-written with D. Deputy and G. Andersen

    Books (single authored)

    • Controlled Foreign Companies and Tax Avoidance. International and Comparative Perspectives with Specific Reference to Polish Tax and Constitutional Law, EU Law and Tax Treaties, C.H. Beck: Warsaw (2020)
    • Opodatkowanie zagranicznych spółek kontrolowanych (CFC): Konieczność reformy, Warsaw, Wolters Kluwer (2017)

    Book chapters (single authored)

    • Will BEPS redefine how countries will design domestic GAARs? Spot on the PPT’s key constituencies, in M. Butani, T. Jain (ed.), ‘General Anti-Avoidance Rules: The Final Tax Frontier. Indian and International Perspectives’, Thomson Reuters (2021)
    • Implementation and Application of the LOB Clause in BEPS Action 6/MLI: Legal and Pragmatic Challenges, in A. P. Dourado (ed.), International and EU Tax Multilateralism: Challenges Raised by the MLI, IBFD 2020.
    • Chapter 6: The GAAR (Article), in W. Haslehner, G. W. Koefler, A. Rust (eds.), A Guide to the Anti-Tax Avoidance Directive, Edward Elgar Tax Practice Series (2020).
    • Strengthening CFC Rules in a Compatible Way with EU Law under BEPS Action 3 in Light of the European Commission’s Proposal – A Critical Evaluation, in R. Danon (ed.), Base Erosion and Profit Shifting (BEPS): Impact for European and international tax policy, Zürich: Schulthess, 2016

    Book chapters (co-authored)

    • Identifying the Potential and Risks of Integration of AI to Taxation: The Case of General Anti-Avoidance Rule, in G. Aviv, P. D’Agostino and C. Piovesan (eds.), Leading Legal Disruption: Artificial Intelligence and a Toolkit for Lawyers and the Law, Thomson Reuters Canada (2021), co-written with Kamil Tyliński
    •  Poland – Branch Report, in IFA (ed.), Qualification of taxable entities and treaty protection, Cahiers de droit fiscal international, Vol. 99b, IFA Congress in Mumbai, Indie, 2014, co-written with P. Goździowska and T. Wickiel
  • Seminars and talks (selected)
    • Explainable Artificial Intelligence in Tax Law, IX Nationwide Scientific Conference on Tax Law „Contemporary Problems of Tax Law”, 8-10 October 2021, Zakopane, Poland
    • General Anti Avoidance Rule: Poland, The course Tax Planning and Theory of Abuse: Comparative Law offered by the Instituto Brasileiro de Direito Tributário (IBDT) Full Master in Tax Law, 25 June 2021, (online) São Paulo, Brazil
    • The Settlement of Tax and Tax Treaty Disputes by the International Courts and Tribunals, The workshop series of webinars Globalization and Digitalization: Interconnections Between Taxation, Trade, and Investment” organized by ERC Project GLOBTAXGOV Leiden University in cooperation with the Council on Economic Policies, the Asia Pacific FDI Network and the School of Law of the City University of Hong Kong, 17 June2021, (online) Hongkong
    • Decision in X GmbH (CJEU), PPT subjective test: burden of proof, PPT versus ‘guiding principle’ in Commentary on Article 1 2017 OECD MC, Global online three-day conference entitled Changing the Global Tax Landscape for Foreign Direct Investments: The Importance of Economic Substance, 25.03.2021, 16, 23 and 25 March 2021, (online) Warsaw, Poland
    • Bilateral Investment Treaty Arbitration: Cairn & Vodafone Awards - What next?, IFA India Virtual Masterclass, 9 January 2021, (online) New Delhi, India
    •  Tax Planning, SGH Warsaw School of Economics in Part Time Master Studies (the module on tax optimization), 9 January 2021, (online) Warsaw, Poland
    •  New Technologies in the Lawyer’s Professional Work, Legal MBA,  27 November 2020, (online) Warsaw, Poland
    • The GAAR in the ATAD, The 12th GREIT Lisbon Summer Course, 22-26 June 2020, (online) Lisbon, Portugal
    • Controversies regarding WHT in Poland from 1 January 2019: Due Diligence and the Beneficial Owner, The workshop for the National Chamber of Tax Advisers in Poland, 29 April and 27 May 2020, (online) Warsaw, Poland
    • An Introduction to the Use of AI in Tax Domain, The workshop for the Ministry of Finance of Poland New Technologies in Tax Domain, 29-30 October 2019
    • Tax Compliance: Exploiting the Potential of AI, Robotics and Data Analytics, Global Tax Technology Conference Real Time Tax Compliance and AI Applications: Identifying the Legal, Regulatory and Cultural Constraints, The Universite de Geneve, 9-10 October 2019, Geneve, Switzerland
    • Controlled Foreign Companies (CFC) rules, Principal Purposes Test (PPT): After- BEPS Anti-Treaty Abuse Standard and its Context and Prospective Consequences Principal Purposes Test, Artificial Intelligence in International Tax Law Domain: Case Study of the Principal Purpose Test (PPT)”, Instituto Brasileiro de Direito Tributario (IBDT) Specialisation Course on International Tax Law, Artificial Intelligence and Tax Law, IBDT open seminar, Tax Incentives in Poland: Tools to Strengthening the Commercial Relationship between Poland and other states, The Selected Issues of the Principal Purpose Test (PPT), IBDT Full Master in Tax Law, 27-31 August 2019, São Paulo
    • PPT subjective test: burden of proof and PPT versus ‘a guiding principle’: Mirrors or does not mirror?, Full day international conference at the De Industrieele Groote Club in Amsterdam, the Amsterdam Centre for Tax Law, 3 May 2019, Amsterdam, The Netherlands
    • Poland’s IP Box Regime: A Tool to Strengthening the IP-Commercial Relationship between Japan and Poland, The Polish-Japanese Investment Forum, Gajoen Tokyo Hotel, 17 April 2019, Tokyo, Japan
    • Poland’s IP Box Regime: Moving towards the Technology and Knowledge-based Economy, Workshop of the OECD Expert Network on R&D Tax Incentive Design and Indicators The design, cost, implementation and cross-border dimensions of R&D tax incentives, BEIS Conference Centre, 22 March 2019, London, United Kingdom
    • Implementation and Application of  Principal Purposes Test (PPT), European and International Tax Law – Master’s Programme, School of Economics and Management, Lund University, 5 February 2019, Lund, Sweden
    • Implementation and Application of  Principal Purposes Test (PPT), Seminar of Swedish Branch of International Fiscal Association, 4 February 2019, Stockholm, Sweden
    •  Strategy of Poland against Tax Havens, The Assembly of Directors, Ministry of Finance (Poland), 10 January 2019, Otwock, Poland
    • Decoding the Principal Purpose Test (PPT) via Knowledge-Based AI, Workshop on MET-ARG „Argumentation and Evidence”, Institute for Philosophy & Sociology at the Polish Academy of Sciences, 15 September 2018, Warsaw, Poland
    • Artificial Intelligence and International Tax Law: Addressing Principal Purpose Test (PPT) via Self-Learning Algorithms, Tax Law Professor’s seminar at the University of Amsterdam, 11 July 2018, Amsterdam, The Netherlands
    •  Artificial Intelligence in International Tax Law Domain: Case Study of the Principal Purpose Test (PPT)”, 4th Summer ELSA Law School on International Tax Law, 5-7 July 2018, Cracow, Poland
    •  Implementation of Limitation on Benefit Clauses: Legal and Pragmatic Challenges, 13th Annual GREIT Conference at the University of Lisbon on Multilateralism and International Tax Law, 18-19 June 2018, Lisbon, Portugal
    • Conflicts of Qualifications in International Tax Law: MLI, SGH Warsaw School of Economics in Postgraduate Studies on International Tax Strategies, 16 June 2018 Warsaw, Poland
    • Using AI to Address International Tax Avoidance: Starting with the PPT”, Open Seminar at the Instituto Brasileiro de Direito Tributario (IBDT), Articles 1, 2 and 3 of the OECD Model Tax Convention, International Tax Law courses at the IBDT, 2-4 April 2018, São Paulo, Brazil
    •  Artificial Intelligence Tax Treaty Assistant:  Decoding the Principal Purposes Test (PPT), a commentator, then: Assistant Professor Eliza Mik (SMU School of Law), Singapore Management University, 22 March 2018, Singapore
    • The AI Technologies and Augmentation of Tax Advisors’ Work: Focus on Treaty Abuse, Virtual Tax Summit 2018, 15 March 2018, online
    • Using AI to detect abuse of tax treaties (BEPS Action 6), Virtual Tax Summit 2017, 5-7 December 2017, online
    • Constitutional Issues arising from the Principal Purposes Test (PPT): The Lesson from Poland, First Edition of Expert Seminar on Tax Law “Theoretical Consequences of Implementation of the BEPS Project for the Polish and International Tax Law”, Maria Curie Sklodowska University, Lublin, Poland, 20 October 2017
    • Prevention of Treaty Abuse under the MLI - Part 2: LOB Rule as Ineffective and Unwanted Overreaction of Mind-Numbing Complexity, Singapore Management University, 10 October 2017, Singapore
    • Prevention of Treaty Abuse under the MLI - Part 1: The Principal Purposes Test (PPT) as Vague and Unbalanced King of the Minimum Standard, Singapore Management University, 26 September 2017, Singapore
    • Treaty Abuse under Multilateral Instrument: Does Active Business or Genuine Activity Matter?, International Tax Conference “Future of Taxes in Disruptive Times”, Singapore Management University, 17 August 2017, Singapore
    • The CFC Rule under the Anti-Tax Avoidance Directive, International Tax Conference “International & European Tax Coordination”, 9th edition of the GREIT Lisbon Summer Course, 19-23 June 2017
    • Articles 1, 2 and 3 of the OECD Model Tax Convention, Course on International Tax Law, Instituto Brasileiro de Direito Tributario (IBDT), 6-8 March 2017, São Paulo, Brazil
    • Preventing Tax arbitrage via Hybrid Mismatches: BEPS Action 2 and Developing Countries, International Conference “A Sustainable Path for Tax Transparency in Developing Countries”, 27 June 2016, 2016, Oslo, Norway
    • Revealing the World of Multinational Tax-Avoidance, University of Oslo, 5 April 2016 Oslo, Norway
    • CFC rules, BEPS Action 3 (Draft) and EU law, Jean Monnet round Table Seminar at the WU chaired by Prof. Dr. Pasquale, 27 April 2015, Vienna, Austria
    • Controlled Foreign Companies and Tax Avoidance: International and Comparative Perspectives with Specific Reference to Polish Tax and Constitutional Law, EU Law and Tax Treaties, PhD seminar on Companies and Markets EU and Nordic company and financial market law, 8-11 December 2014, Oslo, Norway
    • Tax Treaty Interpretation by Supreme Courts: Case Study of CFC rules, International Tax Conference “International Tax Principles in BRICS and OECD Countries: Divergences and Convergences”, IFA-IBDT, 30 September - 1 October 2013, São Paulo, Brazil
  • Publications


    • Kuzniacki, B. (2022). Rzeczywisty beneficjent a podatek u źródła: Alokacja dochodu czy przeciwdziałanie nadużyciom międzynarodowego i unijnego prawa podatkowego. Wolters Kluwer Polska.
    • Kuzniacki, B., Almada, M., Gorski, L., Zeldenrust, R., Tylinski, K., & Winogradska, B. (2022). Towards eXplainable Artificial Intelligence (XAI) in Tax Law: The Need for a Minimum Legal Standard. World Tax Journal, 14(4), [4].
    • Kuźniacki, B. (2022). <i>X-GmbH v Finanzamt Stuttgart</i> – <i>Körperschaften</i>: Abuse of Tax Law and Exchange of Tax Information in EU law. Case note on: CJEU, 26/02/19, C-135/17, ECLI:EU:C:2019:136 (X-GmbH v Finanzamt Stuttgart – Körperschaften). The Modern Law Review, 85(2), 488-506. [details]



    • Kuzniacki, B. (2022). Beneficial Ownership in International Taxation. (Elgar Tax Law and Practice). Edward Elgar Publishing.
    • Kuzniacki, B. (2022). Błędna wykładnia koncepcji beneficial ownership na gruncie polsko-meksykańskiej umowy o UPO wobec organizacji zbiorowego zarządzania prawami autorskimi. Przegląd Podatkowy, 373(5), 47-58. [3].
    • Kuzniacki, B. (2022). Ewolucja krajowej definicji koncepcji beneficial ownership w podatku u źródła: Quo vadis, Domine? Przegląd Podatkowy, 370(2), 44-58.
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  • Ancillary activities
    • PwC
      Tax advice
    • Lazarski University
      Research Assistant Professor