Executive summary

On 30 April 2026, the Organisation for Economic Co-operation and Development (OECD) released The Global Minimum Tax Implementation Toolkit (the Toolkit) to support tax administrations with establishing a robust and efficient domestic compliance framework.

The Toolkit is structured as a roadmap to the key steps and actions that tax administrations commonly undertake in implementing the Global Minimum Tax (GMT), setting out a series of implementation steps, each elaborated through complementary models. The Toolkit was developed by the OECD Forum on Tax Administration, with insights from delegates of the OECD/G20 Inclusive Framework. It builds on the Global Anti-Base Erosion (GloBE) Model Rules and other standards agreed by the Inclusive Framework. It does not interpret or modify the application or interpretation of these standards.

The accompanying press release also mentions that tax administrations of implementing jurisdictions are working together to alleviate any compliance or coordination challenges that could arise from delays that a jurisdiction might encounter in providing Multinational Enterprise (MNE) Groups with access to the Globe Information Return (GIR) filing portal or in activating exchange relationships with other implementing jurisdictions

On the same date, the OECD also released an updated set of Frequently Asked Questions (FAQs) on the GloBE Model Rules and the Global Minimum Tax. The FAQs address practical aspects of the operation of the Global Minimum Tax, including safe harbors, interaction with other tax regimes and administrative features.

Detailed discussion

Background

In October 2021, the OECD released a statement reflecting the high-level agreement of Inclusive Framework member jurisdictions on core design elements of Pillars One and Two of the Base Erosion and Profit Shifting (BEPS) 2.0 project. (See EY Global Tax Alert, OECD releases statement updating July conceptual agreement on BEPS 2.0 project, dated 11 October 2021.)

Since the October 2021 agreement was reached, the OECD has released a series of significant documents agreed by the Inclusive Framework on the Global Minimum Tax under Pillar Two, including:

• The GloBE Model Rules
• (See EY Global Tax Alert, OECD releases Model Rules on the Pillar Two Global Minimum Tax: Detailed review, dated 22 December 2021.)
• The Commentary to the GloBE Model Rules
• (See EY Global Tax Alert, OECD releases Commentary and illustrative examples on Pillar Two Model Rules, dated 21 March 2022.)
• Guidance on GloBE Safe Harbours
• (See EY Global Tax Alert, OECD/G20 Inclusive Framework releases document on safe harbors and penalty relief under Pillar Two GloBE rules, dated 21 December 2022.)
• Five packages of GloBE Administrative Guidance
• (See EY Global Tax Alerts: OECD/G20 Inclusive Framework releases Administrative Guidance under Pillar Two GloBE Rules: Detailed Review, dated 9 February 2023; OECD/G20 Inclusive Framework releases additional Administrative Guidance on Pillar Two GloBE Rules: Detailed review, dated 21 July 2023; OECD/G20 Inclusive Framework releases additional Administrative Guidance on Pillar Two GloBE Rules and update on Pillar One Amount A timeline, dated 22 December 2023; OECD/G20 Inclusive Framework releases fourth tranche of Administrative Guidance on Pillar Two GloBE Rules, dated 28 June 2024; and OECD releases new documents on GloBE rules and on qualified jurisdiction status, dated 17 January 2025.)
• A standard template for the GIR
• (See EY Global Tax Alert, OECD/G20 Inclusive Framework releases document on Pillar Two GloBE Information Return, dated 24 July 2023 and OECD releases new documents on GloBE Information Return, dated 21 January 2025.)
• A package for a "side-by-side arrangement"
• (See EY Global Tax Alert, OECD releases Side-by-Side Package on Pillar Two Global Minimum Tax: Detailed review, dated 16 January 2026.)

The OECD has periodically updated the Commentary to incorporate the agreed Administrative Guidance, releasing Consolidated Commentary to the GloBE Model Rules in April 2024 (which incorporates the three tranches of Administrative Guidance issued before the end of 2023 and in May 2025 (which incorporates all the tranches of Administrative Guidance that had been issued by the end of March 2025).

In addition, in June 2024, the OECD released a Question & Answer document providing information regarding the peer review process for determining the qualified status of the elements of the Global Minimum Tax that are implemented by jurisdictions. (See EY Global Tax Alert, OECD/G20 Inclusive Framework releases documents on Pillar One Amount B and Pillar Two, dated 20 June 2024.) In January 2025, the OECD released a Central Record of Legislation with Transitional Qualified Status, listing the jurisdictions that had completed the transitional qualification mechanism process for the Income Inclusion Rule, the Domestic Minimum Top-up Tax or the Qualified Domestic Minimum Top-up Tax (QDMTT) and QDMTT Safe Harbour, together with explanatory information (including an update to the Q&A document on the process for determining qualified status). (See EY Global Tax Alert, OECD releases new documents on GloBE rules and on qualified jurisdiction status, dated 17 January 2025.) The OECD has periodically updated the Central Record of Legislation with Transitional Qualified Status.

Key features of the Toolkit

The Toolkit is intended for tax administrations and is structured as a practical roadmap covering the full Pillar Two implementation lifecycle. Key features include:

• Modular structure covering the implementation journey: The Toolkit follows a staged approach, beginning with assessment of in-scope multinational enterprise MNE Groups and potential revenue impacts, and extending through legislative design, administrative preparation, compliance procedures and information exchange.
• Focus on administration and compliance frameworks: The Toolkit sets out best practices for tax administrations on the design and operation of domestic compliance procedures for Pillar Two, including registration, filing, payment, verification and enforcement processes.
• Best practices informed by early implementers: The Toolkit identifies common challenges faced by jurisdictions and highlights practical approaches adopted by early implementing countries.
• Exchange of information and IT considerations: The Toolkit includes guidance on operationalizing the exchange of GIRs, managing large data volumes and developing or adapting IT systems to support Pillar Two administration.
• Nonbinding guidance: The Toolkit does not interpret or modify the GloBE Model Rules or agreed Administrative Guidance. It is intended to support consistent application of the Global Minimum Tax as a common approach.

The Toolkit states that although it is intended for use by tax administration and tax policy officials, it could be useful for other stakeholders as well. It also notes that occasional updates may be made to the Toolkit as implementing jurisdictions gain more experience with respect to the global minimum tax rules.

GIR filing deadline

For MNE Groups with a calendar year-end, the first GIR should be filed by 30 June 2026. The press release accompanying the publication of the Toolkit implicitly reflects that tax administrations may not be ready with the infrastructure to support the filing of the GIR. Furthermore, the GloBE Model Rules allow for central filing of the GIR in a jurisdiction that has a Qualifying Competent Authority Agreement in place with the respective local jurisdiction. For jurisdictions to be able to exchange GIRs, an active exchange relationship needs to be in place.

The press release indicates that tax administrations of implementing jurisdictions are working together to alleviate any compliance and coordination challenges that could arise from delays that a jurisdiction might encounter in providing MNE Groups with access to the GIR filing portal or in activating exchange relationships with other implementing jurisdictions. No further information has been provided regarding what this means for MNE Groups.

Updated FAQs on the GloBE Model Rules and Global Minimum Tax

The updated FAQs expand on prior explanations of the Global Minimum Tax and the GloBE Model Rules, reflecting developments agreed by the Inclusive Framework since earlier versions of the FAQs, the most recent version being dated May 2025. In particular, the updated FAQs incorporate explanations of recently agreed design, simplification and administrative features of the Global Minimum Tax. Key elements include:

• Overview and scope of the Global Minimum Tax: The FAQs further clarify the design of the Global Minimum Tax, the application of the effective tax rate (ETR) test and the operation of the Income Inclusion Rule, Undertaxed Profits Rule and Domestic Minimum Top-up Tax, reflecting the current state of agreed Pillar Two rules.
• Interaction with other tax rules: The FAQs expand the explanation of how Pillar Two interacts with controlled foreign company (CFC) regimes, tax incentives and other domestic tax rules, including updated discussion of coordination mechanisms intended to mitigate double taxation and the allocation of taxes under certain CFC and cross-crediting regimes.
• Safe harbors and simplifications: Updated guidance is provided on the application of transitional and permanent safe harbors, including new FAQ coverage of the Simplified ETR Safe Harbour and the Side-by-Side system, which were not addressed in earlier versions of the FAQs.
• Substance and the Global Minimum Tax: The updated FAQs also address the treatment of substance under Pillar Two, including the application of the Substance-Based Income Exclusion (SBIE) and new explanatory material on substance-based tax incentives (SBTI) and the SBTI Safe Harbour.
• Top-up Tax calculations and compliance aspects: Additional explanatory guidance is provided on Top-up Tax calculation mechanics, timing differences and information reporting obligations, reflecting greater implementation experience and the availability of more developed administrative frameworks.

Implications

The Toolkit is directed at tax administrations, but it provides some insight into how jurisdictions may approach the practical administration and enforcement of Pillar Two rules. The updated FAQs provide further information related to the operation of the Pillar Two rules. In addition, the accompanying press release reports that tax administrations may alleviate compliance challenges related to the timely filing of the GIR. Companies should continue to monitor developments in the countries that are relevant to their business.