Research Theme

International Tax

Low-income countries are more dependent on corporate income tax revenue than richer countries, and at the same time, disproportionately affected by multinational tax avoidance. Our research on this theme investigates ways in which developing countries can protect their tax bases, including through simplified transfer pricing methods and improved tax treaty policies. It also examines the challenges and opportunities developing countries face from their participation in international tax negotiations.

ICTD has also been closely following the developments around the UN Tax Convention. Check out our latest research and analysis here.

Led By

Martin Hearson

Key Resources

Working Paper

Global Rules, Local Realities: Lessons from the Global South on International Tax Standards

June 2026

Martin Hearson, Frederik Heitmüller, Florian Dierich

Working Paper

Scenarios for Negotiating a UN Framework Convention on International Tax

January 2025

Frederik Heitmüller

Partner Publication

A Fairer Global Tax Architecture

September 2024

Martin Hearson, Frederik Heitmüller, Mbakiso Magwape, Suranjali Tandon

Journal Article

Relieving Double Taxation on Cross-Border Services: A Comparative Analysis of Major Exporting Countries

July 2026

Frederik Heitmüller, Aisha Aize Isa, Florian Dierich, Yvette Nakibuule Wakabi

International Tax Library

Research in Brief

Is Transparency Enough? An Examination of the Effect of the Extractive Industry Transparency Initiative (EITI) on Accountability, Corruption and Trust in Zambia

April 2024

Sidonie East

Multilateral Carbon Tax Treaty (MCTT)

April 2024

Tatiana Falcão

Working Paper

A Climate Treaty for the Global Taxation of Carbon

April 2024

Tatiana Falcão

Research in Brief

Are Trade Rules Undermining Taxation of the Digital Economy in Africa?

March 2024

Karishma Banga, Alexander Beyleveld

Working Paper

Are Trade Rules Undermining Taxation of the Digital Economy in Africa?

February 2024

Karishma Banga, Alexander Beyleveld

Research in Brief

Tax Treaty Shopping and Developing Countries: Serious Potential for Tax Revenue Losses

November 2023

Maarten van ’t Riet, Arjan Lejour

Working Paper

Is Transparency Enough? An Examination of the Effect of the Extractive Industry Transparency Initiative (EITI) on Accountability, Corruption and Trust in Zambia

October 2023

Sidonie East

Working Paper

Tax Treaty Shopping and Developing Countries

September 2023

Maarten van ’t Riet, Arjan Lejour

Working Paper

Inclusive and Effective International Tax Cooperation: Views From the Global South

August 2023

Lucinda Cadzow, Martin Hearson, Frederik Heitmüller, Katharina Kuhn, Okanga Okanga, Tovony Randriamanalina

Working Paper

Tax Treaty Norms Among Lower- Income Countries and the Role of the UN Model: Past, Present and Potential

August 2023

Martin Hearson, Frederik Heitmüller, Vincent Arel-Bundock

Journal Article

Unsuccessful Implementation of the OECD Transfer Pricing Guidelines in Low Income Countries: The Case of Ethiopia

July 2023

Nathanael Tilahun, Abebe Gebrehiwot Yihdego

Research in Brief

Diffusion of OECD Transfer Pricing Regulations in Eastern Africa: Agency and Compliance in Governing Profit-Shifting Behaviour

May 2023

Cassandra Vet

10 August 2026

The UN Tax Convention draft protocol on cross-border services: clear direction but crucial details left open

Frederik Heitmüller

The much awaited Co-Lead’s draft protocol on the taxation of income from cross-border services was published on 20 July 2026….

4 August 2026

Double taxation relief on remote services – implications for UN Tax Convention Protocol 1 negotiations

Frederik Heitmüller, Aisha Aize Isa, Florian Dierich, Yvette Nakibuule Wakabi

To inform ongoing negotiations on the taxation of cross-border services at the UN, we wrote a study on double tax…

26 November 2025

A new era or business as usual? Why the UN Expert Committee on Tax is still relevant

Florian Dierich

The Committee’s most prominent contribution is the UN Model Tax Convention, which provides model language for the negotiation of bilateral…

4 November 2025

UN Tax Convention Reading List Part 3: Protocol 2 – Dispute Resolution and Prevention

Florian Dierich, Frederik Heitmüller

In Part 3 of our UN Tax Convention reading list, we bring together key research and analysis on dispute prevention…

31 October 2025

UN Tax Convention Negotiations: Where are we at and where are we headed?

Frederik Heitmüller, Florian Dierich

In preparation for the Nairobi session, two documents were shared for discussion: a Framework Convention Template prepared by the Co-lead…

8 October 2025

UN Tax Convention reading list part 2: Protocol 1 – Taxation of cross-border services

Florian Dierich, Frederik Heitmüller

The negotiations for Protocol 1 present a genuine opportunity to revisit how cross-border services are taxed. But, as we explored…

21 September 2026

Call for Papers: Research workshop on the UN Framework Convention on International Tax

Frederik Heitmüller, Martin Hearson

With only one year to go, the negotiations on the UN Framework Convention on International Tax Cooperation and its…

27 July 2026

ICTD launches report on 15 years of research and the future of development finance

The International Centre for Tax and Development (ICTD) has officially released its major report, Taxing Smarter: Advancing Reform Through Research…

29 June 2026

New ICTD research shows uneven adoption of international tax standards by lower-income countries

Martin Hearson, Frederik Heitmüller

This paper by Martin Hearson, Frederich Heitmüller and Florian Dierich, draws together findings across all seven country case studies, identifying…

20 March 2026

Tax treaties in spotlight as UN Tax Convention negotiations deepen

Martin Hearson, Frederik Heitmüller, Florian Dierich

When member-states convene in New York this August for the fifth substantive session on the UN Framework Convention on International…

30 January 2025

UN Tax Talks: New research highlights key scenarios at next week’s historic negotiations

Martin Hearson, Frederik Heitmüller

New research from the International Centre for Tax and Development (ICTD) provides crucial insights into the challenges and opportunities shaping…

19 November 2024

G20 Brazil: How does taxation fit into the agenda?

Fabrizio Santoro, Vanessa van den Boogaard, Martin Hearson, Max Gallien, Frederik Heitmüller

Researchers from the International Centre for Tax and Development (ICTD) participated in crafting such recommendations in a number of policy…

Academic Symposium on the UN Framework Convention on International Tax Cooperation

Virtual

6 February 2026 – 15:30

•

Timezone: Europe/London

ICTD Research Director Martin Hearson and Associate Postdoctoral Fellow Frederik Heitmüller will be speaking at the Academic Symposium on the UN Framework Convention on International Tax Cooperation, hosted by the International Tax Program at the NYU School of Law.

Lecture: The need for more inclusive, equitable tax and multilateral systems

Virtual

3 December 2025 – 16:00

•

Timezone: Europe/London

Fresh from the UN Tax Convention negotiations in Nairobi earlier this month, Mukumba will discuss why reforming the global tax architecture matters for everyone, not just the global South that is pushing for change.

Conference: Digital Service Taxes: A fair and effective way to tax the data economy?

In person

25 September 2025 – 13:30

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Timezone: Europe/London

Allard Pierson Museum, Oude Turfmarkt, Amsterdam, Netherlands

ICTD Research Officer Florian Dierich will be presenting the Centre’s research in a panel exploring policy options around an “improved DST” compared to other alternatives.

WEBINAR: Next Steps for the UN Convention on Tax: Mapping Priorities

Virtual

16 July 2025 – 14:00

•

Timezone: Europe/London

Countries around the world are losing billions to illicit financial flows, tax avoidance, tax evasion, and unfair allocation of taxing rights—reflecting a global tax framework which is no longer fit for purpose. The UN Framework Convention on International Tax Cooperation