After the first filing: where Pillar 2 goes next

While much of the attention surrounding Pillar 2 has focused on technical rules, calculations and compliance obligations, the experience of the first filing season demonstrated that the real challenge extended far beyond tax technical expertise. Success required the ability to coordinate stakeholders, data and deliverables across multiple jurisdictions, often under demanding timelines and with varying levels of local authorities’ experience with Pillar 2 topics. 

The technical layer: data, and a vacuum of interpretation 

The data burden was always going to be a major factor in Pillar 2 filings, and it was indeed a significant hurdle for organisations to overcome. A full GloBE calculation can draw on between 250 and 300 data points per jurisdiction, much of it never previously gathered for tax purposes. Transitional safe harbours ease this, letting many jurisdictions pass a simplified test rather than a full calculation, but even qualifying demands data that groups do not always hold in usable form. 

The subtler problem is one no software resolves on its own: first-year filings were prepared, in effect, in an interpretive vacuum. Positions had to be taken on judgement, documented, and applied consistently wherever the same facts recurred. Across jurisdictions, this lack of clarity could be either an opportunity or a huge risk of misalignment, depending on the approach. 

The coordination layer: a centralised model created a solid foundation  

If the technical challenge was expected, the coordination challenge caught many organisations off guard. Pillar 2 is by design a group-level framework that resolves into local filings, and managing that translation across a large footprint is a huge undertaking. Groups that spread the work across several advisers frequently found the pieces did not fit: effort was duplicated, positions were inconsistent, and errors crept into the seams. A human factor compounded this, as local teams often did not appreciate the importance, or the sheer burden, of Pillar 2 until it landed on them. 

In the first year of implementation, our experts found that the answer was to stop treating a global obligation as a collection of local ones. Forvis Mazars built a single connected structure around the filing effort, with four parts that reinforce one another:  

• A Pillar 2 Executive Committee provides strategic leadership and keeps technical positions aligned across the network.  
• A global network of Pillar 2 Champions carries that alignment into individual countries and feeds local knowledge back, closing the awareness gap before deadlines rather than during them.  
• The Forvis Mazars Pillar 2 Tool applies one consistent methodology across jurisdictions and strengthens quality control.  
• A dedicated Coordination Centre in Portugal directs the effort, working alongside local teams to prepare GloBE Information Returns and local filings at scale. 

No single component is comprehensive in isolation, but together they turn a fragmented, error-prone exercise into a repeatable process. 

Strategies for future cycles of Pillar 2 filings 

The long runway to the first filing is now in the rearview mirror. With clearer expectations, the focus shifts from getting it done to doing it efficiently and at scale, as further jurisdictions bring their rules into force. A centralised model makes that possible: expanding into new territories extends a structure that already exists rather than starting fresh each time. Those who invested in that infrastructure during the first filing will reap the benefits in subsequent cycles, while those who didn’t will need to prioritise centralisation moving forward. 

Technology, including AI, will bring significant efficiencies, but sequencing matters. Because so much guidance arrived late, the first cycle was spent building processes without full sight of the end state; automating on top of processes still forming would have been a mistake. Even for future cycles, over-focusing on efficiency is unlikely to yield significant results. But moving forward, with better established processes and the right tooling at the centre, efficiency gains will be possible. Pillar 2 can help justify tax technology investment, even if it is rarely the sole reason to make it. 

The real achievement of the first cycle was not the filings themselves. It was the demonstration that governance, a local-expert network, a common tool and a central delivery function can combine into a single, consistent client experience across borders – the foundation that recurring compliance will now be built upon. 

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