Tetyana Payosova practises international trade law, with a particular emphasis on WTO law and preferential trade agreements, international dispute resolution, and also advises on EU regulatory and trade matters.

International trade law

Tetyana advises clients on procedural and substantive aspects of WTO law. She represents governments at every stage of WTO dispute settlement proceedings. Tetyana advised clients in a number of WTO disputes involving a broad range of substantive areas, including trade in goods, technical barriers to trade, safeguards, subsidies, government procurement, trade facilitation, as well as general and security exceptions.

Tetyana also advises governments and corporate clients on WTO negotiations (environmental goods and services, fisheries subsidies, e-commerce), on the compatibility of domestic legislation and practice with WTO law and on a broad spectrum of issues arising under bilateral and regional trade agreements.

Prior to joining Van Bael & Bellis, Tetyana advised private companies and governments on various aspects of WTO law in her capacity as fellow at the Institute for International Economic Law and the World Trade Institute of the University of Bern. Tetyana also interned with the Peterson Institute for International Economics (PIIE) in Washington D.C.

EU trade and regulatory matters

In addition to international trade law, Tetyana advises clients on EU regulatory and trade matters. Her practice focuses particularly on environmental, climate change and energy-related issues.

Tetyana advises corporate clients, industry associations, export promotion agencies and governments on the design and trade aspects of recent EU regulatory initiatives, including the EU CBAM Regulation, the Deforestation-Free Products Regulation, the Critical Raw Materials Act, the Net-Zero Industry Act and the Forced Labour Products Ban Regulation, as well as on EU sustainability requirements and EU renewable energy legislation.

Tetyana has been involved in several EU anti-subsidy and safeguard investigations. She also advises clients on foreign direct investment screening, export control and sanctions.

Previously, Tetyana also gained experience in international (rail) transport law and data protection as a legal adviser at the International Rail Transport Committee (CIT), an international association of railway and shipping companies.


Ukrainian, Russian, English, German, Portuguese, French


  • The Best Lawyers 2023: International Trade (Switzerland)
  • Who’s Who Legal (Global Guide): Trade & Customs


  • University of Lausanne, CAS in the Regulation of Global Sport, 2022
  • University of Bern, Switzerland, PhD in Law, summa cum laude, 2020
  • Harvard Law School, LL.M., 2018
    2018 Salzburg Lloyd N. Cutler Fellow, Frank E.A. Sander Writing Prize, Dean’s Community Leadership Award
  • University of Bern, Switzerland, Master of Law, European and International Law, magna cum laude, 2009
  • National University Odessa Law Academy, Ukraine, Bachelor of Law, 2006 and Master of Law, summa cum laude, 2007


Tetyana Payosova has published widely in the area of international law. Recent illustrative examples include:

‘Likeness and environment in the GATT years’ in in P. Delimatsis and L. Reis (eds) Trade and Environmental Law, Volume XI of the Elgar Encyclopedia of Environmental Law (Edward Elgar, 2023) (together with I. Van Damme)

SCM: export subsidies and the environment’ in P. Delimatsis and L. Reis (eds) Trade and Environmental Law, Volume XI of the Elgar Encyclopedia of Environmental Law (Edward Elgar, 2023)

World Trade Organization, in F. Graafsma and J. Cornelis (eds), The International Trade Law Review, 8th edition (2022) (together with J. Redelbach)

‘Re-designing the WTO Mediation Mechanism’ in M. Elsig, R. Polanco and P. van den Bossche (eds), International Economic Dispute Settlement: Demise or Tranformation? (Cambridge University Press, 2021)

The Dispute Settlement Crisis in the World Trade Organization: Causes and Cures, PIIE

Policy Brief 18-5, March 2018 (together with G.C. Hufbauer and J.J. Schott).

‘COTIF Uniform Rules concerning the Contract of International Carriage of Passengers (CIV UR) and Goods (CIM UR)’ in P. Mankowski (ed.), Commercial Law. Article-by-Article Commentary (Nomos, 2018) (together with E. Evtimov)

‘Mitigation (Renewable Energy)’ in K. Nadakavukaren Schefer and T. Cottier (eds.), Elgar Encyclopedia of International Economic Law (Edward Elgar, 2017).

‘Regulatory Takings in the Renewable Energy Sector and FET: Regulatory Coherence for Trade and Investment in Renewable Energy’, in T. Cottier and I. Espa (eds.), International Trade in Sustainable Electricity: Regulatory Challenges in International Economic Law (Cambridge University Press, 2017) (together with S. Matteotti-Berkutova).

‘Promoting Green Electricity through Differentiated Electricity Tax Schemes’, in T. Cottier and I. Espa (eds.), International Trade in Sustainable Electricity: Regulatory Challenges in International Economic Law (Cambridge University Press, 2017) (together with K. Holzer and I. Espa).

‘The Principle of Proportionality in International Law: Foundations and Variations’, 18(4) Journal of World Investment and Trade 628 (2017) (together with T. Cottier, R. Echandi, R. Liechti and C. Sieber-Gasser).

‘The Jurisprudence of the World Trade Organization in 2015’, 26(2) Swiss Review of International and European Law 327 (2016) (together with M. Hahn, R. Liechti and A. Schlaepfer).

‘Selling the Sun Safely and Effectively: Solar Photovoltaic Standards and Implications for trade Policy’ (together with Sunny Rai), in Gary C. Hufbauer, R. Melendez-Ortiz and Richard Samans (eds), The Law and Economics of a Sustainable Energy Trade Agreement (Cambridge University Press, 2016), reprint of the ICTSD Working Paper (2013).

Teaching Positions

Tetyana has taught, among others, at the University of Bern and the PHW Bern Business School, Switzerland and regularly gives seminars and guest lectures on international trade law, WTO law and EU regulatory matters.

Bar Admission 

New York 


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