77th Annual IFA Congress
Lisbon, Portugal
SEMINAR E SESSION REPORT
IFA/OECD
Wednesday 8 October 2025 | 8:30-11:45
Chair
Armando Lara Yaffar (Mexico)
Panel members
Gert Boulangé (Belgium) – Tax Director at InBev SA
Pat Brown (USA) – National Tax Office Co-Leader in PWC US
Belinda Chan (Singapore) – Head of Tax in Temasek
Prof. Dr. Robert Danon (Switzerland) – Partner in Danon and Chair of PSC
Prof. Dr. Christian Kaeser (Germany) – Global Head of Tax in Siemens and Co-Chair of BIAC
Giorgia Maffini (UK) – Tax Director with PWC Tax UK
Mercy Mbithi (ATAF) – Tax Expert at the African Tax Administration Forum
Claudia Pimentel (Brazil) – Undersecretary of Taxation of Receita Federal do Brasil
Tim Power (UK)– Director of Business and International Director and Co-chair of Inclusive
Framework
Dr. Achim Pross (OECD)– Deputy Director within the OECD's Centre for Tax Policy and
Administration (CTPA).
Manuel de los Santos (OECD) - Head of the OECD Transfer Pricing Unit.
Daniel Smith (USA) – International Tax Director at Google and Co-Chair BIAC
Prepared by Secretary
Roberto Padilla Ordaz (Mexico)
1. Introduction
This Seminar E focused on the latest developments in international taxation, and brought together experts from Government, academia, business, and tax practitioners to discuss major international tax initiatives and developments, with a particular emphasis on the work of the OECD.
The panel covered both current and future tax priorities through a high-level overview of international tax issues and trends. Discussions were arranged in four blocks: (1) Global minimum tax, (2) Fostering growth, (3) Global mobility, and (4) Simplification and tax certainty, and allowed interactions from the panelists through insights on current concerns from each other’s perspective.
The Panel’s main objectives were to inform the current developments of the OECD in international taxation and to allow panelists to address their perspectives on such developments and current trends, providing insight based on their professional practice.
2. Main Topics Discussed
2.1. Topic 1: Global Minimum Tax
An initial overview of the Global minimum tax in numbers was provided: 56 jurisdictions have enacted the minimum tax (33 non-EU countries), while 9 jurisdictions communicated their intention to implement or have a draft legislation. Also, a current standing report with respect to the progress of the OECD work in terms of the Global minimum tax was shared.
The panel conducted a comprehensive comparison of the Global minimum tax and the US system, from the following angles: scope, tax base, blending, covered taxes, timing differences, substance carve-out, and rate.
Discussion among panelists was varied, especially on views about the implementation of Pillar 2 rules. This part led to a more contrasting position of some panelists on their approach to Pillar 2 implementation, primarily on the actual adoption possibility for some jurisdictions and the challenges being faced by those that have already adopted such rules.
2.2. Topic 2: Fostering Growth
This topic was introduced with a description of the workstream at OECD on tax policies for growth, focusing on policy tools such as accelerated depreciation, R&D incentives, and tax certainty. Panelists also provided valuable input from a governmental and private sector perspective in some jurisdictions with respect to current and future policies that are intended to foster growth.
Key messages were addressed on the following matters:
Focus on the balance: Effective and efficient tax systems balance revenue generation with cost efficiency to ensure better economic outcomes and long-term sustainability.
Understand costs: Analysing product costs helps shape optimal tax policies and, therefore, better economic outcomes.
Choose Optimally: Once more is known about costs, the most efficient tax administration products should be chosen, especially if it is desired not to distort the economy and/or a competitive environment
2.3. Topic 3: Global Mobility
Results of the Global Workforce Hopes & Fears Survey 2024, which features 50 countries representing 90% of global GDP, were addressed. This survey is a global research study aiming to understand the attitudes and behaviours of the global Results show that nearly half of the jobs can now be done remotely; 1 in 5 is performed entirely in person. Other results of the survey are:
Asia Pacific has the highest % of remote workers (full or hybrid), followed by North America.
Western Europe and Latin America lead on hybrid work.
Africa and Latin America display the highest percentage of full in-person.
To the question of who is more mobile, many factors determine such a situation, such as generation, technological adoption, seniority, and financial situation.
Additional aspects were addressed, such as business taxation (home office PE, transfer pricing, and residence), personal income taxation (employment income, one-stop-shop, frontier workers, social security), and applicable regimes, digital nomads and other relevant challenges.
As part of the development of OECD work, by 2025 year-end, an updated version of the OECD Model Convention Commentaries will be released, addressing matters on Home Office PE and other related topics. Phase 2 of these efforts includes an upcoming Inclusive Framework Plenary in 2026.
2.4. Topic 4 - Simplification and Tax Certainty
The panel highlighted that an overview of OECD/IF/FTA Tax Certainty work was carried out, including insight from the roundtable and upcoming Tax Certainty Day, and a focus on key issues and ongoing workstreams– simplifications, Amount B, Tax certainty & transfer pricing, increased need for Advance Pricing Agreements (APA) and Mutual Agreement Procedures (MAP), teaser on Tax Certainty day, G20 work, Tax administration 3.0 and digitalization.
It was mentioned that in various earlier events, commentators made the valid point that it is often not one single item that improves the overall tax certainty landscape, but how various aspects work together and also how administrations use the tools that tax policy makers provide.
A strawman with cross-border tax certainty tools was presented in order to show elements of policy and practice, based on 3 major aspects: clarity and certainty of policy framework, dispute prevention to avoid unnecessary adjustments, and dispute resolution.
A cross-examination was provided in such a strawman in order to evaluate tax certainty tools as briefly described:
Clarity and certainty of policy framework, based either on legislative framework or regulatory framework.
Dispute prevention to avoid unnecessary adjustments, based on advanced certainty, taxpayer engagement, risk assessment, and tax audit and verification.
Dispute resolution based on domestic dispute resolution remedies, bilateral and multilateral MAP arbitration, and efficient, effective, and timely administration practices.
3. Conclusions
Seminar E provided an interesting insight into recent and upcoming work developed by the OECD, enriched with interaction from panelists from academia, private, and government sectors, where different concerns and positions were exposed. Implementation of Pillar 2 prevails as a primary concern from different economic sectors; however, the panel allowed for in-depth discussion on several other relevant topics in the international taxation arena.