Executive summary

On 22-23 November 2025, G20 Leaders met in Johannesburg, South Africa, under the South African G20 Presidency to address major global challenges and to promote solidarity, equality and sustainability as key pillars of inclusive growth. The meeting concluded with the release of the Leaders' Declaration, which includes a section on international tax.

The declaration references continued constructive engagement to address concerns regarding Pillar Two global minimum taxes, with "the shared goal of finding a balanced and practical solution that is acceptable for all as soon as possible." These efforts are to be advanced in close cooperation across the membership of the Organisation for Economic Co-operation and Development (OECD)/G20 Inclusive Framework, preserving the tax sovereignty of all countries.

The declaration also notes ongoing negotiations to establish a United Nations (UN) Framework Convention on International Tax Cooperation, with the participating G20 members reaffirming the objective of reaching a broad consensus while building on existing achievements and avoiding unnecessary duplication of effort. It further addresses other international tax priorities, including global mobility, the interaction between tax policy, inequality and growth, and support for inclusive participation in BEPS and transparency initiatives. Finally, the declaration describes Domestic Resource Mobilisation (DRM) as a shared imperative.

In advance of the meeting, the OECD released the "OECD Secretary-General's Tax Report to the G20 Leaders," which provides an update on activities with respect to the G20's international tax agenda. The OECD also published the report "Enhancing Simplicity to Foster Tax Certainty and Growth," which was prepared for the G20 Finance Ministers and Central Bank Governors.

Detailed discussion

G20 Leaders' Declaration

The Leaders' Declaration released at the conclusion of the G20 Summit contains a section titled "Working together to stabilise the International Tax System and enhance Domestic Resource Mobilisation," which addresses several international tax priorities.

The declaration references continued constructive engagement to address concerns regarding Pillar Two global minimum taxes:

72. We will continue engaging constructively to address concerns regarding Pillar Two global minimum taxes, with the shared goal of finding a balanced and practical solution that is acceptable for all as soon as possible. Delivery of a solution will need to include a commitment to ensure any substantial risks that may be identified with respect to the level playing field, including a discussion of the fair treatment of substance-based tax incentives, and risks of base erosion and profit shifting (BEPS), are addressed and will facilitate further progress to stabilise the international tax system, including a constructive dialogue on the tax challenges arising from the digitalisation of the economy. These efforts will be advanced in close cooperation across the membership of the OECD/G20 Inclusive Framework (IF), preserving the tax sovereignty of all countries.

Noting ongoing negotiations on a UN Framework Convention on International Tax Cooperation, the declaration indicates that participating G20 members reaffirm the objectives of reaching a broad consensus and building on existing achievements, while avoiding unnecessary duplication of efforts. It recalls the Rio de Janeiro G20 Ministerial Declaration on International Tax Cooperation and welcomes the Inclusive Framework's phased, evidence-based approach to explore global mobility and to understand the interaction between tax policy, inequality and growth. (See EY Global Tax Alert, G20 Finance Ministers affirm commitment to BEPS 2.0 and enhanced global tax cooperation, dated 2 August 2024.)

The declaration welcomes update reports on the OECD/G20 BEPS project and transparency initiatives, with the observation that working together has delivered significant progress. The declaration stresses that building "on these gains and ensuring that developing countries can fully participate and benefit will require supporting inclusive participation and enhancing tax capacity tailored to needs." It also notes an opportunity to expand on transparency with a new OECD framework that would "enable interested jurisdictions to strengthen international tax transparency on immovable property on a voluntary basis."

The declaration characterizes DRM as a shared imperative. It underscores that: (1) the deliverables under the South African Presidency demonstrate DRM is the most effective funding source; (2) revenue administration is an essential pillar of the tax system; (3) coordination and collaboration among capacity-building providers are important; and (4) a structured, country-owned and country-led approach to reform that fulfils the social contract with taxpayers is valuable. Finally, the declaration looks forward to the Platform for Collaboration on Tax's Tax and Development Conference on DRM to be held in Tokyo in 2026.

November 2025 OECD Secretary-General Report

The OECD Secretary-General's Report to the G20 Leaders provides an update on key tax developments, similar to the report to the G20 Finance Ministers for their meeting in October 2025. (See EY Global Tax Alert, G20 Chair's Summary cites Pillar Two engagement, dated 21 October 2025.)

The report describes ongoing work on international tax, with updates covering: the OECD's support for G20 initiatives; progress on the Pillar Two global minimum tax; ongoing work on the BEPS minimum standards; new work on tax, inequality and growth and global mobility; tax transparency developments; and work on tax and development.

New report on tax simplification

On 18 November 2025, the OECD published "Enhancing Simplicity to Foster Tax Certainty and Growth," prepared for the G20 Finance Ministers and Central Bank Governors at the request of the South African G20 Presidency. The report analyzes the systemic drivers of that complexity and identifies opportunities for simplification through multilateral cooperation. The complexity stems from the interaction of multiple sovereign tax systems. The report focuses on ways to improve the design of cross-border business income taxation rules, which affect mainly large business taxpayers.

The report discusses five hallmarks of simplicity in tax rules:

1. Clear structure and drafting
2. Coherent interaction with existing rules
3. Limited novelty and frequency of change
4. Practical ease of application for taxpayers in complying
5. Practical ease of application for tax authorities in administering

The report also identifies three main drivers of complexity:

1. The baseline context of large multinational business models
2. Policy choices that trade off simplicity against other objectives, in the context of both fundamental design choices and measures aimed at integrity concerns
3. The rulemaking process, in which consensus building, lack of prioritization of simplification and time pressures can add complexity

The report stresses that rule length alone does not determine simplicity. It further notes that design choices should consider both implementation and audit burdens.

The report then examines the role of multilateral cooperation in tax complexity. It acknowledges that multilateral processes can introduce their own complexities and highlights how multilateral cooperation ultimately can reduce complexities in cross-border income taxation. Coordinated approaches can reduce fragmentation, create a more level playing field, enable more efficient implementation, and allow tax administrations to share experience and administrative burdens.

In the context of multilateral cooperation in cross-border business taxation, the report proposes a "simplicity checklist" that includes five process actions for designing solutions and outputs and five substantive solutions and outputs. The process actions are (1) impact assessment and problem diagnosis, (2) early and ongoing consultation, (3) model rule development and drafting, (4) review of interactions with existing rules, and (5) realistic timelines and consideration of phased approaches. The substantive solutions are (1) transparent articulation of trade-offs between simplicity and other policy goals, (2) inclusion of simplicity as an explicit policy objective, (3) deliberate rule design choices, (4) consideration of taxpayer compliance realities, and (5) support for tax administration capacity.

The report concludes with several proposals for follow-up actions. These include (1) testing the simplicity checklist, (2) enhancing capacity building with a specific focus on simplification, (3) introducing simplicity reviews into model rule development, (4) conducting rationalization reviews to address interactions between new rules and existing BEPS measures, (5) conducting further analysis to support improved targeting of integrity measures, (6) exploring simplifications in areas such as transfer pricing, and (7) advancing work on designing programmable rules.

As a next step, the report suggests that its analysis and ideas could be tested and refined through consultation with a wider group of stakeholders, including interested jurisdictions, international and regional tax organizations, businesses and academics. The outcomes of that consultation, together with the report, could be discussed within forums such as the Inclusive Framework and the OECD Forum on Tax Administration to identify areas of work that members may wish to take forward, either individually, collectively or with other organizations and stakeholders.

Implications

The declaration references the G20 Leaders' continued constructive engagement on addressing Pillar Two concerns and finding a balanced, practical solution that is acceptable to all. It also reflects G20 supports for efforts to stabilize the international tax system, including dialogue on tax challenges arising from the digitalization of the economy. The declaration notes ongoing negotiations on a UN Framework Convention on International Tax Cooperation and the objective of building consensus while avoiding duplication.

It is important for businesses to continue monitoring the international tax discussions in the OECD, the UN and other global and regional forums. Businesses also should keep updated on tax proposals and legislative developments in the jurisdictions relevant to their operations. Looking ahead, with global tax discussions expanding into new areas, businesses may want to consider the opportunities available to engage with policymakers and participate in this important dialogue.