The first Pillar Two ‘Domestic Top-up Tax’ (DTT) reporting cycle is here, and the clock is ticking. With the first GloBE Information Return (GIR) and local DTT filings for the 2024 fiscal year due by June 30, 2026, multinational enterprises (MNEs) operating across Singapore and beyond are navigating the most significant global tax compliance shift in a generation — with very little room for error.
Frequently Asked Questions
| Question | Answer |
|---|---|
| What is the DTT reporting deadline for the first cycle? | June 30, 2026, covering the 2024 fiscal year — the first live reporting window under Pillar Two rules. |
| Who does the Pillar Two DTT apply to? | MNEs with annual consolidated revenues of €750 million or more in at least two of the four preceding fiscal years. |
| What is the Domestic Top-up Tax (DTT)? | A Qualified Domestic Minimum Top-up Tax (QDMTT) that ensures low-taxed profits within a jurisdiction are taxed up to the 15% global minimum effective tax rate locally, before any foreign top-up can apply. |
| What is the GloBE Information Return (GIR)? | The standardised OECD reporting template that MNEs must file, covering up to 480 data points per jurisdiction across 28 pages. |
| Is there any transitional relief available? | Yes. The Transitional CbCR Safe Harbor has been extended to cover fiscal years beginning on or before December 31, 2027 — offering meaningful short-term relief. |
| How many countries have enacted Pillar Two legislation? | Over 60 jurisdictions have enacted Pillar Two legislation as of early 2026, including Singapore. |
| Where can Singapore-based MNEs get specialist DTT support? | Our team at Lee & Hew’s Singapore tax resource hub covers the latest developments and can guide your compliance approach. |
Understanding Pillar Two and the Domestic Top-up Tax (DTT) Framework
Before we get into the reporting cycle itself, it helps to understand what Pillar Two actually is. The OECD’s Pillar Two framework establishes a global minimum effective tax rate of 15% for large MNEs. It was designed to curb profit shifting to low-tax jurisdictions and ensure that governments capture their fair share of corporate tax revenues.
The Domestic Top-up Tax (DTT), also called a Qualified Domestic Minimum Top-up Tax (QDMTT), is one of the core charging mechanisms. When an MNE’s constituent entities in a given jurisdiction pay an effective tax rate below 15%, the local tax authority can impose a top-up charge to bring it to that floor — locally, before any foreign authority can step in to collect under the Income Inclusion Rule (IIR) or Undertaxed Profits Rule (UTPR).
Singapore enacted its own Domestic Top-up Tax as part of its Pillar Two implementation, making it one of over 60 jurisdictions worldwide to adopt these rules. The first live reporting cycle covers fiscal year 2024 and is, for the vast majority of affected MNEs, entirely new territory.
Why the First Pillar Two DTT Reporting Cycle Is Different from Anything Before It
Previous tax compliance cycles, however complex, were largely built on familiar frameworks. The first Pillar Two ‘Domestic Top-up Tax’ (DTT) reporting cycle is genuinely new. There is no prior year to benchmark against, no established audit trail, and for most organisations, no complete technology solution in place.
For the first time, MNEs must calculate their GloBE Effective Tax Rate (ETR) on a jurisdiction-by-jurisdiction basis, reconcile it against the 15% minimum, compute any top-up tax owed, and file a standardised global return — all within the same compliance window as their regular obligations.
The coordination required between tax, finance, IT, and group-level functions is substantial. Many organisations are running these calculations in parallel with existing processes for the very first time in 2026, and the learning curve is steep.
An at-a-glance overview of the 4-step DTT reporting cycle under Pillar Two. It guides readers through how the Domestic Top-up Tax flows from calculation to submission.
The 4 Steps of the DTT Reporting Cycle Explained
The Pillar Two ‘Domestic Top-up Tax’ (DTT) reporting cycle broadly follows four sequential steps. Understanding each one is essential for any MNE preparing its first submission.
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Data Gathering and Scoping: Identify all constituent entities in-scope for the €750 million threshold and collect the financial data required for each jurisdiction. This includes covered taxes, GloBE income or loss, and relevant deferred tax adjustments.
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GloBE ETR Calculation: Compute the effective tax rate for each jurisdiction by dividing the jurisdiction’s adjusted covered taxes by its GloBE income. Compare this to the 15% minimum rate to determine whether a top-up tax applies.
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DTT Computation and Liability Assessment: For jurisdictions with an ETR below 15%, calculate the top-up amount. Apply any applicable safe harbors (such as the Transitional CbCR Safe Harbor) and substance-based income exclusions to reduce or eliminate the liability.
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GIR Filing and Local DTT Return Submission: Complete and submit the GloBE Information Return (GIR) to the relevant local tax authority, alongside any domestic top-up tax return required under local legislation.
Each step carries its own complexity, particularly at the data gathering stage, where the volume of information required is considerably larger than most organisations initially anticipate.
Did You Know?
The GloBE Information Return (GIR) comprises 28 pages and potentially 480 data points per jurisdiction — making it one of the most data-intensive tax filings ever required of multinational enterprises.
Source: Deloitte
The GloBE Information Return: What You Are Actually Filing
The GloBE Information Return (GIR) is the standardised OECD reporting document that sits at the centre of the first Pillar Two ‘Domestic Top-up Tax’ (DTT) reporting cycle. It is not a simple form. At 28 pages and up to 480 data points per jurisdiction, it represents a significant leap in reporting complexity.
For an MNE with operations in, say, 20 jurisdictions, the data burden is already substantial. For a group with 100 constituent entities, the volume of individual data points can run into the tens of thousands across a single reporting cycle. Each data point must be traceable, auditable, and consistent with the group’s financial statements and tax records.
The GIR typically covers the following sections:
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Overview of the MNE group structure and constituent entities
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Jurisdiction-level GloBE income and loss computations
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Covered taxes and deferred tax adjustments by jurisdiction
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Top-up tax calculations, including any applicable safe harbor elections
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Substance-based income exclusions (payroll and tangible assets carve-outs)
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Allocation of top-up taxes between the IIR, UTPR, and QDMTT charging provisions
For Singapore-based MNEs, the GIR is filed with the Inland Revenue Authority of Singapore (IRAS), alongside a separate local DTT return where applicable. Our financial reporting standards resources provide additional context on how these filings interact with existing statutory requirements.
Transitional Safe Harbors: The Relief Mechanisms in the First DTT Cycle
Recognising that the first Pillar Two ‘Domestic Top-up Tax’ (DTT) reporting cycle would place enormous strain on MNEs, the OECD introduced a set of transitional safe harbors to reduce the burden in the early years of implementation.
The most widely used is the Transitional CbCR Safe Harbor, which allows qualifying MNEs to rely on Country-by-Country Report (CbCR) data, rather than full GloBE calculations, to determine whether a jurisdiction’s top-up tax liability is nil for a given period. This safe harbor has been extended by one year, now covering fiscal years beginning on or before December 31, 2027.
Other key transitional reliefs include:
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De minimis safe harbor: Excludes jurisdictions where GloBE revenue is below €10 million and GloBE income or loss is below €1 million.
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Simplified calculations safe harbor: Allows use of simplified ETR tests based on financial accounting data in certain circumstances.
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Substance-based income exclusions: A permanent (not transitional) carve-out reducing top-up tax exposure based on payroll costs and the carrying value of tangible assets in each jurisdiction.
For many MNEs, up to 90% of their jurisdictions may initially qualify for the Transitional CbCR Safe Harbor, which explains why a significant number of groups are still managing their first DTT cycle primarily through spreadsheets rather than purpose-built software.
Singapore’s DTT Rules and What They Mean for MNEs Here
Singapore implemented its Domestic Top-up Tax as part of its broader Pillar Two adoption, effective for fiscal years beginning on or after January 1, 2025. The rules are broadly consistent with the OECD’s Model Rules, with IRAS providing detailed administrative guidance to assist groups in their first reporting cycle.
Key features of Singapore’s DTT regime include:
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A minimum effective tax rate of 15% applied to GloBE income of Singapore-based constituent entities
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Recognition as a Qualified Domestic Minimum Top-up Tax (QDMTT), meaning Singapore collects any top-up due on local profits before a foreign parent can apply IIR charges
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Alignment with the OECD’s administrative guidance on covered tax adjustments, deferred taxes, and substance-based exclusions
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Filing and payment deadlines set in line with the broader GIR submission timetable
Singapore’s existing corporate tax framework, with a headline rate of 17% and various incentive schemes, means that many Singapore-based entities may have effective rates below 15% when GloBE adjustments are applied. It is critical not to assume that a 17% headline rate automatically means no DTT exposure. The GloBE ETR calculation involves several adjustments that can reduce the apparent rate significantly.
Common Data Challenges in the First Pillar Two DTT Reporting Cycle
Every organisation navigating the first Pillar Two ‘Domestic Top-up Tax’ (DTT) reporting cycle faces a version of the same core problem: the data required does not always exist in the format needed, in one place, at the right time.
Here are the most commonly reported data challenges we see in practice:
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Data fragmentation: Financial data for GloBE purposes lives in multiple ERP systems, often across different currencies, accounting standards, and fiscal year-ends.
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Deferred tax analysis: GloBE rules require specific treatment of deferred tax balances that differs from both local GAAP and IFRS, meaning existing deferred tax workings cannot simply be re-used.
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Substance-based exclusion data: Payroll costs and tangible asset carrying values must be gathered at the constituent entity level for every jurisdiction, often requiring input from HR and asset management systems that do not typically interact with tax functions.
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Covered taxes reconciliation: Identifying which taxes count as “covered taxes” under GloBE rules requires a legal and commercial assessment of each jurisdiction’s tax regime.
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Intercompany eliminations: GloBE calculations require careful handling of intercompany transactions and eliminations at the jurisdictional level.
Getting these right the first time matters. Errors in the GIR are not just administrative problems — they can affect the group’s top-up tax liability, trigger audit attention, and create cascading inconsistencies across multiple jurisdictions’ local returns.
Did You Know?
58% of corporate tax departments report being under-resourced for Pillar Two requirements in 2026, up from 51% the year prior — and the first DTT filing deadline has not yet passed.
Source: Thomson Reuters
Resource Pressures: What the First DTT Cycle Is Costing Tax Teams
The statistics paint a clear picture. The majority of corporate tax functions are entering the first Pillar Two ‘Domestic Top-up Tax’ (DTT) reporting cycle without adequate internal resource. This is not a criticism — it is the reality of implementing a fundamentally new global tax system within existing team structures and budgets.
In response, many organisations are taking one of three approaches:
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Hiring specialists: 38% of tax departments intended to hire additional professionals specifically for the Pillar Two transition. However, the pool of practitioners with hands-on GloBE expertise is limited, and competition for that talent is intense.
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Investing in technology: Purpose-built Pillar Two calculation and reporting software is now available from several providers. These tools can automate parts of the GloBE ETR calculation and GIR population, but they require significant implementation effort and clean data to function reliably.
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Engaging external advisors: Many MNEs — particularly those with Singapore operations — are working with specialist tax advisory firms to manage the first reporting cycle, using that engagement to build internal capability for subsequent years.
The third approach is often the most practical for mid-size MNEs that cannot justify the cost of enterprise-grade software or the time required to hire and onboard new specialists before the June 2026 deadline. Our services include direct support for Pillar Two compliance engagements, and we work with clients to match the right level of involvement to their actual needs — not to sell complexity where it is not needed.
Best Practices for Managing Your First Pillar Two DTT Reporting Cycle
Having seen the first DTT cycle take shape across multiple client engagements, there are several practices that consistently separate the groups managing it well from those that are struggling. Here is what works:
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Start with a scoping exercise: Before any calculations, confirm which entities are in-scope, which jurisdictions are covered, and whether any existing CbCR data is reliable enough to support the Transitional Safe Harbor election. This one step can save weeks of unnecessary calculation work.
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Centralise ownership: The GloBE ETR calculation touches finance, tax, legal, and IT. Assign a single point of accountability for the end-to-end process, with clear workstreams for each function.
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Don’t assume the safe harbor applies: The Transitional CbCR Safe Harbor is valuable, but it requires the underlying CbCR data to meet quality thresholds. Validate your CbCR data quality before relying on it to support a nil top-up determination.
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Document everything: This is the first cycle. Tax authorities in multiple jurisdictions are learning these rules at the same time as taxpayers. Thorough documentation of methodology, elections, and data sources protects you in the event of a future audit or query.
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Plan for year two now: The transitional reliefs available in the first reporting cycle will narrow over time. Use this year to build the data infrastructure and internal processes that will support a sustainable ongoing compliance approach.
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Get advice on Singapore-specific issues early: Singapore’s DTT rules interact with the country’s unique incentive regime in ways that are not always obvious. Entities benefiting from development and expansion incentives, pioneer status, or other concessionary rates require careful ETR analysis.
How Lee & Hew Approaches Pillar Two and DTT Compliance
Complexity — seen it, done it, resolved it. The first Pillar Two ‘Domestic Top-up Tax’ (DTT) reporting cycle is precisely the kind of challenge where the difference between a generalist and a specialist matters most.
At Lee & Hew, we approach DTT compliance the same way we approach every technical engagement: with grounded expertise, honest advice, and a clear focus on what you actually need to get done. We are not here to make this more complicated than it needs to be. We are here to make sure you get it right.
Our team combines deep technical knowledge of Singapore tax and international frameworks with practical experience in financial reporting and regulatory compliance. We understand how the GloBE rules interact with Singapore’s existing corporate tax landscape, and we know where the real risks tend to sit for groups of different sizes and structures.
For MNEs that need support with their first DTT reporting cycle, we offer:
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Scoping and jurisdictional risk assessments
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GloBE ETR calculations and top-up tax quantification
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Transitional safe harbor review and documentation
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GIR preparation support and local DTT return filing assistance
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Ongoing Pillar Two advisory as the rules evolve
We look after you — and we don’t let you down. If you want to understand where you stand before the June 2026 deadline, talk to our team. Your success is our commitment.
What this all means
The first Pillar Two ‘Domestic Top-up Tax’ (DTT) reporting cycle is not a distant obligation. For MNEs with fiscal years ending December 31, 2024, the filing deadline is June 30, 2026 — and that is closer than it looks when you factor in the data gathering, calculations, reviews, and approvals that must happen before submission.
This cycle is genuinely new. The GloBE Information Return is unlike any tax filing that has come before it, and the Domestic Top-up Tax mechanics require a depth of analysis that goes well beyond traditional effective tax rate calculations. But it is manageable — provided you start with a clear picture of your obligations, use the available transitional reliefs intelligently, and have the right expertise on hand.
Whether you are navigating your first DTT cycle entirely in-house, or you need a specialist partner to guide you through it, the important thing is not to wait. The rules are live. The deadline is set. Business is never like before — and this is exactly the kind of moment where getting grounded, practical advice makes all the difference.
Contact us now to find out more!
Lee & Hew Public Accounting Corporation