The UN Tax Convention: the government’s chance to stand for economic justice

Next week, delegates from across the world will converge on Nairobi, Kenya, for two weeks of negotiations on the new UN Tax Convention.

This is potentially a landmark treaty that could finally make it possible to tax the super-rich and global corporations fairly. If successful, the convention would mark the beginning of a new era of international tax justice – one where wealth is no longer hoarded by a tiny elite while billions go without the basics.

The system is rigged

These talks come at a pivotal moment for the global economy. Wealth inequality is accelerating at breathtaking speed. We are on track to see the world’s first trillionaires within a decade. Elon Musk has already signed a trillion-dollar contract with Tesla. Meanwhile, ordinary people everywhere are facing stagnant wages, crumbling public services, and deepening poverty. Every year, countries lose over half a trillion dollars to tax dodging by big corporations and the super-rich – and it’s the countries of the global South that lose out the most.

The UN Tax Convention offers a way out of this broken system. It could bring measures for real transparency – such as public country-by-country reporting of corporate profits – and coordination to tackle tax avoidance. Likewise, it could fix the deeply unjust rules that allow multinationals to shift profits across borders to minimise their tax bills.

Instead of taxing profits where companies are headquartered (usually in the global North), a fairer system would tax global profits and allocate taxing rights based on where companies actually do business – reflecting real economic activity. That’s the kind of change that could transform global revenues and start to level the playing field between rich and poor nations.

This process also lands amid growing global calls to tax extreme wealth. In the UK, dozens of MPs, unions and civil society groups have demanded a wealth tax. Internationally, Brazil – as G20 president – has championed the idea too. The main argument against wealth taxes has always been that the ultra-rich might flee if asked to contribute their fair share. But that’s exactly what the UN Tax Convention can solve: through international coordination, transparency, and a global asset registry that makes it harder for billionaires to hide their wealth in property, shell companies or luxury goods.

Nairobi to Belem

The timing of these talks – taking place alongside COP30 in Brazil – is both symbolic and vital. The climate crisis is, at its heart, a crisis of inequality and exploitation. Countries in the global North have grown rich through centuries of fossil fuel extraction and pollution, effectively appropriating the world’s shared carbon budget. They owe a multi-trillion dollar climate debt to the global South, which is bearing the brunt of floods, droughts and rising seas it did little to cause.

Climate finance will be central to CO30. Without huge public, grant-based transfers from North to South – to support adaptation and mitigation, and to compensate for loss and damage – the world will not be able to address climate breakdown. The UN Tax Convention could become a powerful vehicle to raise this finance. The treaty’s terms of reference mentions environmental taxes, creating space for bold measures such as a global fossil fuel excess profits tax. Such a tax, based on the “polluter pays” principle, could see oil and gas giants paying into a global climate action fund.

A test for the UK

The UK’s record on this issue is poor. When Nigeria and the Africa Group put forward the 2023 UN resolution to establish the convention, the UK was one of its staunch opponents. When the proposal passed, the UK doubled down – joining the USA, Canada, Australia, New Zealand, South Korea, Japan, and Israel to vote against the Terms of Reference, earning themselves the monica the “Hurtful Eight”. They were joined shortly after by Argentina. Being part of this awkward squad of countries with leaders like Trump, Milei and Netanyahu must have been an uncomfortable position..

For the UK, the Tax Convention is a chance to build meaningful partnerships with countries in the global South – something the government claims to want. This is especially true in an era of shrinking aid budgets – if the government is going to slash ODA, the least it could do is support a tax system that would allow Southern nations to raise their own revenues. The UK’s status as the world’s biggest enabler of tax dodging –  thanks to its network of offshore havens from Jersey to the British Virgin Islands – only underscores the need to make up for bad reputation. 

Now, with the US having theatrically stormed out of the talks, the UK is more exposed than ever. It faces a clear choice: side with Washington’s wrecking tactics and cling to defunct, OECD-led alternatives – or work with the rest of the world to build a fair, transparent tax system under the UN that can actually deliver justice. If it fails to back this process, Britain’s credibility on international cooperation will evaporate entirely.

What comes next

These negotiations are just the beginning. Over the next two years, delegates will meet three times annually in New York and Nairobi to draft the convention’s text, aiming for ratification in 2027. After that, the convention will establish annual “COPs” – similar to the climate process – where countries will meet to expand and strengthen the framework through new mechanisms and protocols.

If countries show courage and vision now, this could become a turning point: the UN Tax Convention could do for economic justice what the UNFCCC has done for climate – create a living, evolving space for progressive multilateral action. But it depends on political will. For the UK and for the world, the choice is clear: cooperate to build a fairer global tax system, or continue protecting the super-rich at everyone else’s expense.