Cross-border Tax Talks

Pillar Two update: More filing challenges

Doug McHoney (PwC’s International Tax Services Global Leader) is joined by Phil Ramstetter, a Chicago-based International Tax Partner at PwC and Pillar Two subject matter specialist. Phil previously served as a tax policy consultant at Business at OECD (BIAC). Doug and Phil discuss the evolving Pillar Two landscape, including the OECD’s 2026 guidance, BIAC’s role in shaping workable rules, and the side-by-side and UPE safe harbors. They examine UTPR allocation and GIR validation problems arising from differences in domestic laws, alongside new guidance on explicitly conditional taxes and mismatched QDMTT fiscal years. The conversation also covers revised GIR and XML reporting, continuing QDMTT compliance for US-parented groups, upcoming guidance on related benefits and integrity measures, and why greater taxpayer input, prospective rulemaking, and filing standardization are essential to meaningful simplification.

• [00:45] – Introduction of Phil Ramstetter, his PwC role, previous experience at BIAC, and the Cincinnati Reds, St. Louis Cardinals, and rookie standouts.
• [02:30] – What role does BIAC play in influencing OECD tax policy?
• [04:10] – Why is greater taxpayer involvement needed to address practical Pillar Two data and compliance challenges?
• [06:15] – What are the major OECD Pillar Two developments in 2026, including the side-by-side safe harbor?
• [07:15] – Additional guidance for 52/53-week filers, GIR updates, and September administrative guidance.
• [08:30] – How are jurisdictions implementing Pillar Two and the side-by-side agreement?
• [09:25] – What GIR validation challenges are emerging ahead of the March 2027 compliance deadline?
• [10:15] – How do differences between domestic legislation and OECD model rules create UTPR top-up tax reporting discrepancies?
• [13:30] – Why do employee and tangible asset allocation formulas create UTPR calculation and validation problems?
• [15:20] – The challenges of applying UTPR rules across multiple jurisdictions with differing domestic requirements.
• [17:20] – How should multinationals reconcile local legislation with OECD guidance and manage expanding filing requirements?
• [19:10] – September 2026 guidance on explicitly conditional taxes and mismatched QDMTT fiscal periods.
• [24:00] – How do local financial accounting standards interact with QDMTT fiscal-year alignment requirements?
• [25:00] – Treatment of partial-year accounting periods arising from acquisitions, disposals, liquidations, and formations.
• [26:30] – New guidance permitting required QDMTT fiscal years that differ from the ultimate parent entity's fiscal year.
• [28:35] – How do the side-by-side and UPE safe harbors differ, and what relief do they provide?
• [30:25] – What challenges do the revised GIR and XML schema create for the 2026 reporting cycle?
• [32:35] – Managing overlapping compliance, accounting, and implementation cycles across multiple tax years.
• [33:25] – Why do US-parented multinationals still face substantial GIR and QDMTT reporting obligations under the side-by-side safe harbor?
• [35:20] – What additional OECD guidance is expected on related benefits, tax incentives, and integrity measures?
• [37:00] – Could broad integrity and anti-arbitrage measures inadvertently penalize ordinary business transactions?
• [38:05] – Why should future OECD administrative guidance apply prospectively rather than retroactively? Is Pillar Two becoming simpler, or more complex?
• [39:35] – The continuing QDMTT compliance burden and limitations of simplified ETR and transitional safe harbors.
• [41:00] – Why are standardized forms and streamlined filing requirements increasingly important?
• [42:50] – Could more targeted, risk-based reporting reduce unnecessary compliance obligations?
• [43:20] – Should the transitional country-by-country reporting safe harbor become permanent?

View full podcast series