PRESS STATEMENT
Country-Level Revenue Estimates – A Comparative Analysis of UN and OECD Subject to Tax Rules for 65 Member States of the G-24 and South Centre
Washington and Geneva, 23 July 2025
The South Centre & Group of Twenty-four today jointly released country-level revenue estimates of the UN & OECD Subject to Tax Rule (STTR) for their 65 combined Member States.
Results show higher revenues from UN STTR, and reinforce benefits of a UN Tax Convention.
Comparison of Tax Revenue Effects of United Nations and OECD Subject to Tax Rule for G-24 and South Centre Member States
By Faith Amaro and Sol Picciotto
The Subject to Tax Rule (STTR) seeks to address the historical imbalance in the allocation of taxing rights under international tax treaties by introducing within existing treaties a new article which makes the restrictions on source taxation conditional on the residence jurisdiction imposing a minimum level of tax on foreign-derived income. This paper presents a methodology for analysing the respective benefits of the STTRs developed by the Organisation of Economic Co-operation and Development (OECD) and the United Nations (UN). Applying this model to publicly available data for 2021, it also provides estimates of the possible revenue impact for the 65 Member States of the South Centre (SC) and the Intergovernmental Group of 24 (G-24). Our analysis indicates that the OECD STTR would have no impact on any OECD country treaty with a SC/G-24 Member State. Applying the prescribed 9% minimum rate to covered payments, only 100 treaties across 28 SC/G-24 Member States would qualify for improvement under the OECD STTR, with an estimated combined revenue gain of USD 55.6 million, 71% of which is concentrated in just five treaties. In contrast, the UN STTR, which does not specify a minimum rate, was modelled using rates of 9%, 10% and 15%. This resulted in estimated revenue gains of USD 212 million, USD 325 million, and USD 1,165 million across 171, 210 and 317 treaties, respectively. Given its complexity and restrictive scope, it seems pointless for any SC/G-24 Member State to join the OECD STTR. Instead, countries should focus on identifying treaties that cause unjustifiable revenue losses and consider revising them – either by adopting the simpler and broader UN STTR or implementing other measures such as active anti-abuse provisions to combat treaty shopping and tax avoidance.
Analysing the Impact of UN and OECD Subject to Tax Rule for G-24 and South Centre Member States
By Suranjali Tandon and Chetan Rao
The Subject to Tax Rule (STTR) is meant to address base erosion and profit shifting in cross –border transactions. The United Nations (UN) and Organisation for Economic Co-operation and Development (OECD)/Group of Twenty (G20) Inclusive Framework have developed models of the STTR that countries may choose to adopt in their treaties. This paper provides a review of these designs of two STTR models and proceeds to estimate the revenue gains for the Intergovernmental Group of Twenty-Four on International Monetary Affairs and Development (G-24) and South Centre Member States that may arise from a STTR that covers different kinds of payments. The OECD STTR is limited to related-party payments and imposes thresholds based on mark-up and materiality, reducing its applicability in practice. In contrast, the UN STTR offers broader coverage, applies to both related and unrelated parties, and does not impose restrictive thresholds, making it more administratively feasible for developing countries. Although the estimated gains from the OECD STTR appear modest due to its narrow scope, the UN STTR shows greater potential. The analysis also highlights data limitations and the need for access to microdata for accurate country-level assessments.
G-24 South Centre Call For Papers: Comparing tax revenues to be generated from United Nations and OECD Subject To Tax Rule (STTR)
Deadline – 1 July 2024
The G-24 and the South Centre have launched this Call For Papers providing funding for studies which can produce country level comparative revenue estimates of the UN and OECD STTR on the 65 combined Member States of the South Centre (available here) and the G-24 (available here). The data should clearly provide how much revenue each Member State will get if they opt for the UN STTR vs the OECD STTR. The objective is to help Member States of both intergovernmental organizations make informed decisions on adopting the version of the STTR which is more beneficial to them.
Member States of the G-24 and the South Centre are advised to wait till the publication of the results of this study before taking a decision on whether or not to sign the OECD STTR MLI.
Beyond the Two Pillar Proposals
A Simplified Approach for Taxing Multinationals
By Sol Picciotto, Muhammad Ashfaq Ahmed, Alex Cobham, Rasmi Ranjan Das, Emmanuel Eze, Bob Michel
This paper puts forward an alternative to the proposed multilateral convention under Pillar One of the BEPS project, by building on and going beyond the progress made so far. A new direction was signalled in 2019 by the G-24 paper proposing a taxable nexus based on significant economic presence, combined with fractional apportionment. The resulting measures agreed under the two Pillars entail acceptance in principle of this approach, and also provide detailed technical standards for its implementation. These include: (i) a taxable nexus based on a quantitative threshold of sales revenues; (ii) a methodology for defining the global consolidated profits of MNEs for tax purposes, and (iii) detailed technical standards for defining and quantifying the factors that reflect the real activities of MNEs in a jurisdiction (sales, assets and employees).
The time is now right to take up the roadmap outlined by the G-24. The work done shows that technical obstacles can be overcome, the challenge is essentially political. This paper aims to provide a blueprint for immediate measures that States can take, while engaging in deliberation at national, regional and international levels for a global drive towards practical and equitable reforms. Unitary taxation with formulary apportionment is the only fair and effective way to ensure taxation of MNEs where economic activities occur, as mandated by the G20. It can ensure that MNE profits are taxed once and only once, provide stability and certainty for business, and establish a basis for international tax rules fit for the 21st century.
* Also available in French, Spanish, Portuguese and Arabic.
TAXING MULTINATIONALS: THE BEPS PROPOSALS AND ALTERNATIVES
BEPS Monitoring Group, 6 July 2023
This briefing by the BEPS Monitoring Group (BMG) analyses the outcomes of the latest phase of the G20/OECD project on base erosion and profit shifting, and outlines options and alternatives, especially for developing countries. The BMG is a network of experts on various aspects of international tax, set up by a number of civil society organizations which research and campaign for tax justice including the Global Alliance for Tax Justice, Red de Justicia Fiscal de America Latina y el Caribe, Tax Justice Network, Christian Aid, Action Aid, Oxfam, and Tax Research UK. This report has not been approved in advance by these organizations, which do not necessarily accept every detail or specific point made here, but they support the work of the BMG and endorse its general perspectives. It is based on previous reports, and has been drafted by South Centre’s Abdul Muheet Chowdhary, Alex Cobham, Emmanuel Eze, Tommaso Faccio, Jeffery Kadet, Bob Michel, and Sol Picciotto.
Statement by the South Centre on the Two Pillar Solution to Address the Tax Challenges Arising from the Digitalisation of the Economy
28 July 2023
The South Centre takes note of the Outcome Statement by 138 member jurisdictions of the OECD/G20 Inclusive Framework (IF) made on 11 July 2023, on the Two-Pillar Solution to Address the Tax Challenges Arising from the Digitalisation of the Economy. In this statement the South Centre highlights the inclusion of rules that have the practical effect of reducing the tax payable to developing countries under Amount A, the limitations of Pillar Two and other key aspects of the OECD proposed rules that require attention by developing countries before they decide to be tied up by such rules.
Enforcing Secondary Taxing Rights: Subject to Tax Rule in the UN Model Tax Convention
By Abdul Muheet Chowdhary and Sebastien Babou Diasso
The Global Anti Base Erosion (GloBE) Rules under OECD’s Pillar Two recommendations, with a minimum effective tax rate of 15%, are expected to play a significant role to end the ‘race to the bottom’ in corporate taxation, which is one of the main drivers of profit shifting. However, the thrust of these rules is designed in a manner to give priority to the developed countries. In this light, the Subject to Tax Rule (STTR), which is a treaty-based rule that allows source jurisdictions to impose limited source taxation on certain payments that are taxed below a minimum rate in the country of residence, is of extreme significance for the developing countries. Under Pillar Two, application of STTR is restricted to base eroding payments or mobile income between related parties only, which does not address Base Erosion and Profit Shifting (BEPS) concerns in an entirety. That apart, the withholding tax rate of 9% proposed by the OECD may not result in generation of significant resources for the developing countries. In this light, developing countries keenly expect that the UN Tax Committee should devise an STTR that is simple to operate, has a broad scope covering all payments in a tax treaty and imposes a higher withholding tax closer to 15% to bring meaningful revenues for them. Also, developing countries desire that STTR provisions may be introduced at the earliest so as to speedily implement them through the UN Multilateral Instrument under contemplation. This Policy Brief also examines existing average withholding tax rates on interest and royalty payments in existing tax treaties of 48 South Centre and 52 G-77+China Member States and finds that out of a total of 100 developing countries, only 25 would stand to benefit from the STTR in its restricted form in Pillar Two, further strengthening the need for an improved version formulated by the United Nations.
Climate Finance Withholding Mechanism: Exploring a potential solution for climate finance needs of the developing countries
By Radhakishan Rawal
The developed countries’ commitment to provide climate finance to the developing countries has remained unfulfilled. The Climate Finance Withholding Mechanism (CFWM) is a potential solution for addressing climate finance needs of the developing countries. The CFWM adopts the well settled “withholding mechanism” under the tax laws to provide a steady flow of funds to the developing countries.
Multinational enterprises’ (MNEs) tax residents of developed countries earn income from the developing countries and pay tax on such income in the developed countries. The CFWM requires retention in the developing country, of the amount of tax so payable by the MNE, towards climate finance commitments of the developed countries. The CFWM does not result in additional tax outflow for the MNEs and also does not adversely impact taxing rights of the developed countries. The CFWM results in application of tax revenue of the developed countries towards their climate finance commitments. The CFWM does not address all the issues related to the climate finance problem but only attempts to speed up the flow of funds to the developing countries from where the relevant income originates.
Impact of a Minimum Tax Rate under the Pillar Two Solution on Small Island Developing States
By Kuldeep Sharma
The Research Paper commences with an overview of Pillar One and Pillar Two followed by detailed discussions on salient provisions of Pillar Two.
Pillar Two is envisaged to have a widespread impact on Small Island Developing States (SIDS) which are a distinct group of 38 United Nations (UN) Member States and 20 Non-UN Members/Associate Members of UN regional commissions that are exposed to unique social, economic and environmental vulnerabilities. In all, 36 SIDS that are members of the Group of Seventy-Seven (G-77) have been analysed, namely, Antigua and Barbuda, Bahamas, Bahrain, Barbados, Belize, Cabo Verde, Comoros, Cuba, Dominica, Dominican Republic, Fiji, Grenada, Guinea-Bissau, Guyana, Haiti, Jamaica, Kiribati, Maldives, Marshall Islands, Mauritius, Federated States of Micronesia, Nauru, Papua New Guinea, Samoa, São Tomé and Príncipe, Seychelles, Singapore, Solomon Islands, St. Kitts and Nevis, St. Lucia, St. Vincent and the Grenadines, Suriname, Timor-Leste, Tonga, Trinidad and Tobago, and Vanuatu.
