Piet Battiau is the Head of the VAT Unit in the Centre for Tax Policy and Administration (CTPA) of the OECD. He is responsible for the OECD's work on indirect taxes, including the International VAT/GST Guidelines; the OECD recommendations for addressing the VAT challenges of digital trade; helping tax authorities to enforce VAT compliance in digital trade; the OECD’s VAT capacity building work incl. through the development of Regional VAT Digital Toolkits; the Consumption Tax Trends publication; and the OECD Global Forum on VAT. Current priorities include the development of guiding principles for the design and implementation of “digital continuous transactional reporting” (DCTR) regimes for VAT and international policy dialogue on the VAT treatment of crypto-assets. 

Piet joined the OECD in 2011. He began his career as a tax inspector for the Belgian Ministry of Finance in the early 1990’s before moving on to an international financial institution in 1995, where he became Head of International Taxation and subsequently Head of Public Policy. He was also Chairman of the Fiscal Committee of the European Banking Federation. He studied Law in Brussels and Ghent and holds a Law degree and a degree in Tax Science. 

Rodrigo Peñas Blázquez has more than 25 years of professional experience in international logistics, customs and cross border e commerce operations. Throughout his career, he has held senior management positions covering transportation, airline logistics, commercial strategy and operational leadership. In these roles, he has been closely involved in the practical handling of high volume international trade flows and the associated VAT and customs processes. Since 2021, he has been CEO of CACESA Tech & Logistics, where he is responsible for the strategic development of large scale B2C e commerce customs clearance models. His professional focus lies on the interaction between logistics, customs automation and VAT relevant processes in mass e commerce, supported by proprietary IT systems and AI based solutions designed to ensure efficiency and legal certainty.

Han Bosch holds over 36 years of experience in the Customs Administration of The Netherlands. From mid-2021 he is working at the EU Commission in Brussels, in DG-Taxud, sector Customs Legislation, unit e-commerce. He was involved in the development of the customs legislation and explanation of the EU e-commerce package (July 2021) and the e-commerce part of the new Union Customs Code as agreed upon in March 2026. In addition, he contributed intensively to the e-commerce Framework of Standards of the World Customs Organization. Han acquired an in-depth knowledge in the fields of customs supervision and is recognized for active input in national and international project and research groups dealing with innovation in supervision. Specialized in e-commerce and related legislative measures and models of data analytics and data exchange amongst customs authorities and the business sector. An experienced open-minded debater and presenter for national and international forums.

Ian is a Deputy Director in Indirect Tax Directorate in HMRC, responsible for International VAT policy. He started his career with HMRC (and its predecessor department HM Customs & Excise) over 30 years ago and has worked in a number of roles, mostly in VAT but also other indirect taxes. For the last 20 years, Ian has been working on VAT policy, including a three-year secondment to HM Treasury (2008-2011), and has broad experience across a range of VAT policy areas, including extensive experience in international forums, including the OECD.

Ad van Doesum studied tax law at Leiden University, specializing in indirect taxes. His career began in October 1998 at EY, working as a tax advisor in the international VAT practice at EY. From 2004 to 2012, he was also a lecturer and researcher at Tilburg University, where he obtained his PhD in 2009 with the dissertation "Contractual Cooperative Arrangements in VAT." He worked at PwC from 2005 until January 1, 2026, ultimately serving as head of the Knowledge Centre at PwC Netherlands. Additionally, from 2012 to 2026, he was a professor of Value Added Taxes at Maastricht University and an honorary judge at The Hague Court. Since January 1, 2026, Ad van Doesum has been appointed as a Justice in the Supreme Court of the Netherlands.

Peter is a senior executive and global leader with extensive international experience in customs, trade laws, and compliance across global postal and e commerce logistics. With over two decades of international leadership experience, he has built a reputation for transforming complex regulatory frameworks into scalable, business enabling solutions — enabling global growth, operational excellence, and sustainable compliance.

Since 2019 Peter is responsible for leading a global team and ensuring compliance across customs, international trade laws and Core Compliance in DHL eCommerce’s organization and operations.

Throughout his career, Peter has held several executive roles across DHL divisions, consistently driving modernization in international gateway operations, and compliance structures. He worked in major M&A activities, steered DHL’s international mail and parcel operations and holds a PhD in engineering and MBA in Customs Administration. 

David Hummel studied law at the University of Leipzig. His academic career starts with the Study of Law at the University of Leipzig, a Graduation (Phd) as an assistant of Prof. Dr. Stadie with a VAT-Thesis in 2009 and a Habilitation in 2013 with the matter: “neutrality of legal forms in public law” (venia legend for public law, especially tax law and public economic law). 

David Hummel is since October 2016 legal secretary (“référendaire”) at the Court of Justice of the European Union in Luxembourg in the chamber of advocate general Juliane Kokott. In mid-2017 the appointment as a Professor at the University of Leipzig took place. Since 2016, he has spent numerous teaching stays abroad in different countries like Luxembourg, United Kingdom and the Netherlands. In April 2026, he left the Court of Justice of the European Union and took over a full professorship and the chair of “Tax Law and Public Law” at the Friedrich-Alexander-University at Erlangen-Nuremberg.

His main research interests are Tax Law and State Aid Law. Since his activity in the CJEU, he is especially focussed on the European Tax Law (direct and indirect taxes) as well as the national tax law with a focus on VAT-Law, the general tax code and the income-taxation of the employees. David Hummel is one of the authors of, inter alia, „Rau/Dürrwächter“ (commentary of the German VAT-Law), „Kirchhof/Söhn/Mellinghoff“ (commentary of the German income tax law) and “Hübschmann/Hepp/Spitaler” (commentary of the German general tax code).

Jelena Knežević is tax advisory and certified auditor. She has been a partner at LeitnerLeitner since 2021.

She is a graduate of the Faculty of Economics, University of Belgrade, and as a Certified Auditor become the member of the Serbian Chamber of Authorized Auditor. Since 2025 she has also served as Chairperson of the Supervisory Board of the Serbian Chamber of Authorized Auditors. 

Ms. Jelena Knezevic has over 21 years of professional experience in finance, of which 20 years as an auditor, tax and financial advisor in Serbia, in domestic and international tax law. Her field of Expertise encompasses: Serbian and international tax law, indirect taxation and VAT, business advice and Business valuation, M&A and transactional advisory, tax structuring of real estate transaction, demergers, debt and equity financing, transfer pricing, tax audit, tax due diligence, tax litigation as well as corporate clients on a wide range of transaction and advisory matters, implementation of International Accounting Standards and audit of financial statements prepared in accordance with IAS/IFRS/Special purpose Framework with an emphasis on direct area: auditing of separate and consolidated financial statements, system scanning, verifying accounting systems and systems of internal control, and financial due diligence. 

She is a highly active and prominent member of various bilateral organizations, participates extensively in the Legal and HR Committee of the German‑Serbian Chamber of Commerce (AHK), and is a member of the coordination body of the group that handles tax and accounting related issues. 

Alongside her advisory work, Ms. Jelena Knezevic is a distinguished speaker at numerous seminars, conferences, and panel discussions organized by high‑profile Serbian and international institutions. She has published numerous articles in Serbian and international publications.

Georg von Streit is a lawyer and certified tax consultant with 35 years of experience. He has worked for DHL Group since 2004, including time spent in Buenos Aires where he was responsible for indirect taxation of the business in Latin America. Later he advised group entities in Africa and Middle East on VAT matters. He is based at the group headquarters in Bonn and in recent years has advised group companies in the Post & Parcel division in particular in connection with the numerous changes to VAT and postal law. Prior to joining DHL, he worked in pwc’s indirect tax group in Hamburg and Brussels. Georg is a regular speaker at tax conferences and the author of various publications.

University Degree in Laws obtained in Universidad Complutense of Madrid. Tax Inspector in the Spanish Tax Authorities since 1999, specially focused on VAT. Heading the Deputy Direction for Legal Assistance in the AEAT since October 2009 till April 2022.

In 2020 he was chosen as one of the external world VAT experts assisting to produce the Toolkit for the VAT in the digital economy for Latin America. Since 2021 he was appointed by, OECD, CIAT. IBFD and IDB to assist the Tax Authorities of Panamá, Dominican Republic, Argentina, Vietnam, Uganda and Saudi Arabia in the implementation of the VAT to the digital economy.

Besides participating as a teacher/lecturer/Spanish delegate in different seminars, working groups and conferences (OECD, EU, IBD, IMF, IOTA, etc.) he has published different articles in Spanish specialized magazines about tax fraud and VAT. 

He is also author of different international articles and courses devoted to European VAT in the International VAT monitor (IBFD) and Linde Publishers (WU University Austria). 

Before joining the European Commission, Ludwig has worked as a tax inspector with the Belgian Ministry of Finance (1989 -1996) and when he joined the Commission more than 20 years ago, he was active in the anti-dumping policy (1996-1997). Subsequently he moved to DG TAXUD, where he was responsible for VAT and administrative cooperation and the fight against VAT fraud. Ludwig was also responsible for the different enlargement processes where he had to verify that candidate countries had adapted their VAT legislation and administrative capacity in order to be allowed to join the EU. He negotiated the different derogations they requested and provided several training sessions both on site and in the countries concerned. When active in the unit dealing with administrative cooperation and fight against VAT fraud he was responsible for the setting up of the Eurofisc network.

Currently he is active in the VAT policy unit of DG TAXUD and responsible for the VAT e-Commerce package, the numerous derogation requests and most recently with the ViDA (VAT in the digital Age) proposal. Ludwig chairs the different working groups whose competence falls withing the remit of the unit (Groupe on the Future of VAT, the VAT Expert Group and the VAT Committee). As acting Head of Unit, he follows all other files within the competence of the unit, including relations with the customs colleagues.

Ludwig also takes part in the meetings at OECD, WCO and IOTA and in bilateral negotiations such as for the Agreement on Administrative cooperation with Norway and Brexit that resulted in the bilateral agreements.

He has a Master Law degree (University of Ghent) and a Master Degree in Business Administration (EHSAL - Brussels).

Karl-Heinz is a Global VAT/GST Practitioner with over 30 years of international VAT/GST technical and practical experience (Tax authorities, Big 4 and 19 years in Industry). He is actively involved in a wide variety of industry and expert policy groups on an EU and international level -  eg, as chair of the Business at OECD VAT/GST work to the OECD and a member of the EU Commission´s VAT Expert Group. In 2021 Karl-Heinz founded an independent international Thought Leadership, Strategy and Policy Affairs company with domain knowledge and understanding of the global VAT/GST policy landscape.

Christian advises clients on all aspects of national and international VAT issues and specializes in customs and excise duty matters. His particular focus is on import VAT related issues as well as optimizing cross-border supply chains and processing schemes. Christian has extensive experience in carrying out SAP-VAT audits and customs reviews. He also assists clients with external audits and represents them in dealings with the tax authorities and before the tax courts. His clients range from individuals to international groups. Prior to joining KMLZ, Christian spent several years working in the VAT department of a large tax consultancy firm. He regularly lectures on VAT and customs related topics, as well as regularly publishing comments, articles and annotations in these areas.