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.
Determining the Upper Bound of the Scoping Criteria for Amount B in the OECD/G20 Two-Pillar Solution: A Policy Guide for Developing Jurisdictions
By Chetan Rao, Ruchika Sharma, and Dr. Vijit Patel
Amount B, a component of the OECD/G20 Two-Pillar Solution, has been designed to simplify transfer pricing for baseline distribution activities. With the aim of developing a practical policy guide for developing jurisdictions to fine tune the quantitative scoping criterion under Amount B, i.e., “annual operating expense to annual net revenue” ratio, this paper critically analyses various aspects of this criterion. The upper bound of this ratio is purported to help jurisdictions in identifying baseline distributors. It is currently set as a flexible range from 20% to 30%, with the choice available to each adopting jurisdiction deciding the exact point in the range for implementation of Amount B within its jurisdiction. Given the lack of any data-backed rationale in the Amount B report for development of this range, the authors suggest that the upper bound range might have been politically negotiated. For this very reason, developing countries need to tread carefully while setting the upper-bound and consider both its tax as well as policy implications. Through an empirical analysis of independent distributors in India, the paper highlights the link between the upper bound, functionality, and profitability, illustrating how these metrics impact developing countries with lower asset and expense intensities. The findings suggest that setting the upper bound at the higher end of the range could unintentionally bring above-baseline distributors into scope, thus foregoing long-term taxing rights for developing jurisdictions. Through this analysis, the paper offers practical insights and recommendations for jurisdictions, especially developing ones, for setting this upper bound to protect their taxing rights and minimize risks of misclassification of above-baseline distributors as baseline.
The Implications of Treaty Restrictions of Taxing Rights on Services, Especially for Developing Countries
By Faith Amaro, Veronica Grondona, Sol Picciotto
Taxation of cross-border services has been identified as a high priority issue in the United Nations (UN) negotiations to establish a new global framework for tax. This paper analyses the defects of international tax rules as applied to services, and their exploitation by multinational enterprises (MNEs), focusing on the impact on developing countries. Services have become increasingly important for economic development, but international tax rules favouring delivery by non-residents act as a disincentive to the growth of local services providers, particularly disadvantaging developing countries which are mainly hosts to MNEs. We analyse the restrictions on source taxation of services in tax treaties, particularly those based on the model of the Organisation of Economic Co-operation and Development (OECD), and show that their spread has been accompanied by a widening deficit in services trade of developing countries, while the weakening of their attempts to protect their tax base through withholding taxes has resulted in increasing losses of tax revenue. The paper combines detailed qualitative analyses of tax treaties with quantitative estimates of their effects on trade and tax revenues for services of five developing countries: Argentina, Brazil, Colombia, Kenya and Nigeria. Our analysis suggests that a new approach is needed for taxation of services, breaking with the residence-source dichotomy, and adopting formulary apportionment. This could be based on the standards agreed in the Two Pillar Solution of the OECD/Group of Twenty (G20) project on base erosion and profit shifting (BEPS) and developed now through the UN.
Analysis of Imbalanced Tax Treaties of Developing Countries
Insights From the Tax Treaties Explorer Database
By Aiwei Feng, Shristi Joshi and Quinn McGannon
This report will start from exploring the historical background, theoretical frameworks, and practical implications of tax treaties, with a specific focus on their impact on developing countries. Utilizing diverse literature and datasets, including the Tax Treaties Explorer (TTE) from the International Centre for Tax and Development, it aims to identify restrictive tax treaties and provisions disadvantageous to developing nations. The methodology involves desk reviews, data analysis, and case studies to offer insights into challenges faced by developing countries in international taxation. By scrutinizing key provisions like those concerning permanent establishment and withholding taxes, it aims to highlight how treaties affect revenue generation, economic sovereignty, and development outcomes of South Centre Member States. South Centre Member States have been chosen for the purpose of this study due to their status as developing countries with much to gain from renegotiating their existing tax treaties.
Ultimately, this study intends to fill the gap in terms of treaty research and development of tax treaties of South Centre Member States by identifying their restrictive tax treaties and provisions therein with Organisation for Economic Co-operation and Development (OECD) countries. The choice of OECD countries reflects their status as mostly developed countries. At the same time, the study also intends to supplement tax treaties literature so far dominated by legal and economic analyses by focusing specifically on identifying specific restrictive provisions.
Painting the Grass Green: A Climate Change Carve-Out in Investment Agreements
By Daniel Uribe
During the Twenty-Eighth Session of the Conference of the Parties (COP-28) of the United Nations Framework Convention on Climate Change (UNFCCC), States recognised the critical need to accelerate efforts to mitigate climate change and called on Parties to take action to transition away from fossil fuels in energy systems, to achieve net zero emissions by 2050. However, implementing such a transition finds obstacles in investor-state dispute settlement (ISDS) mechanisms, which can undermine regulatory actions necessary for climate policies, leading to a ‘regulatory chill’. As a response to these challenges, the Organisation for Economic Co-operation and Development’s (OECD) Future of Investment Treaties program has proposed a model carve-out provision to exclude fossil fuel sectors from ISDS protection with procedural safeguards, but its effectiveness may be limited. A holistic reform of investment agreements and additional measures, such as withdrawal from international investment agreements, are necessary to safeguard regulatory space and promote sustainable investment and a just transition.
A Toss Up? Comparing Tax Revenues from the Amount A and Digital Service Tax Regimes for Developing Countries
By Vladimir Starkov and Alexis Jin
In this paper, we attempt to estimate the tax revenues to be gained by the Member States of ATAF, WATAF, AU and the South Centre under the Amount A and an alternative stylized DST taxation regime. Our research demonstrates that the comparative revenue effects of the Amount A and DST taxation regimes largely depend on (a) the mix of relevant domestic economic activities at market jurisdictions (i.e., revenues sourced to the country as a market jurisdiction under Amount A and the level of revenues from automated digital services generated in the country), (b) design details of the DST regime such as the DST tax rate and the nature of activities to be taxed and (c) the relief from double taxation, if any, countries will grant to domestic and foreign taxpayers under DST. This paper contains analysis relying on sources of information available to private sector researchers and it does not involve review of any information that individual taxpayers provided to tax authorities.
The Design of a UN Framework Convention on International Tax Cooperation
By Sol Picciotto
The creation of a UN-led framework for international tax cooperation is an opportunity for an institutional and conceptual reset, to re-establish a global perspective that has been disrupted by the assumption of an increasingly dominant role in international tax by the OECD. The OECD’s expansive proselytisation of its approach, aiming to encourage foreign investment by restricting taxation of income at source where it derives, has paradoxically taken place in counterpoint with growing concerns about the evident dysfunctionality of that approach. The current process should learn from the past to design a global framework fit for the future, by embodying the aims and general principles that have come to be recognised especially in the recent period as essential guideposts for effective international tax reform.
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.
Multipartisme: est-ce bon pour les pays en développement?
Par Harris Gleckman
Publié par South Centre et Institut Transnational
Résumé exécutif:
Multistakeholderismo: ¿Es bueno para los países en desarrollo?
Por Harris Gleckman
Publicado por South Centre y Instituto Transnacional
Resumen ejecutivo:
