The Global 15% Minimum Tax: What It Is, Who Has Joined, and Why It Matters to Every Business

The world just agreed on a minimum tax rate for large companies. Here is everything you need to understand it.

The Big Idea: No More Tax Havens for Big Multinationals

Imagine a company that earns billions of dollars across the world but pays almost no tax anywhere because it shifts profits to a tiny low-tax country where it has barely any real operations. This has been happening for decades. It costs governments worldwide an estimated USD 150 billion in lost tax revenue every year.

The OECD, an international economic organisation of 38 countries, spent years designing a solution. In 2021, over 140 countries agreed to it. The solution is called Pillar Two, and its core rule is simple: no large multinational company should pay less than 15 percent tax anywhere in the world.

As of 2026, this rule is live. Companies are already being assessed. First filings are due. And the legal and business consequences are real.

Who Does It Apply To?

Not every company. This rule applies only to large multinational enterprise groups, meaning companies that operate in more than one country and have annual global revenues of at least 750 million euros in at least two of the last four years.

If a company's effective tax rate in any country where it operates falls below 15 percent, a top-up tax kicks in to bring it up to that 15 percent floor. The top-up tax is collected either by the country where the parent company is headquartered, or by other countries where the group operates.

Smaller businesses, domestic companies, and groups below the revenue threshold are not affected.

How Does It Actually Work?

Think of it like a floor. If you are in a room with a floor at 15, you cannot go below it no matter what. Similarly, a multinational company may operate in a country that charges only 9 percent corporate tax. Under the old system, that was a perfectly legal advantage. Under Pillar Two, a top-up tax of 6 percent is collected elsewhere to bring the effective rate up to 15 percent.

The OECD designed three mechanisms for collecting this top-up tax. The Income Inclusion Rule allows a parent company's home country to collect the top-up tax on profits of a low-taxed subsidiary. The Qualified Domestic Minimum Top-Up Tax allows the low-tax country itself to collect the top-up tax before any other country can. Most countries have chosen this route because it means the tax revenue stays home. The Undertaxed Profits Rule acts as a backstop, allowing any implementing country to collect top-up tax if neither of the above has been applied.

Which Countries Are In?

Approximately 140 countries in total have committed to the framework. However, commitment and implementation are two different things.

The EU implemented Pillar Two in full across all its member states, effective from 1 January 2024. The UK did the same. Japan, South Korea, Australia, Canada, Switzerland, Singapore, the UAE, and most of the world's major economies have enacted legislation and are now collecting top-up taxes.

India has adopted a wait-and-watch approach. India has not yet enacted Pillar Two legislation, though it has been part of the OECD Inclusive Framework discussions. Indian companies with global revenues above the 750 million euro threshold and operations in countries that have implemented Pillar Two are already affected, because those countries can now apply top-up taxes on profits earned in low-tax jurisdictions, potentially including some Indian operations.

The US Problem: The Biggest Economy That Said No

In January 2026, the US Department of the Treasury announced that US-headquartered companies would be exempt from Pillar Two's requirements. The United States will not be implementing Pillar Two.

This is a significant crack in the global framework. The US has its own minimum tax called GILTI, but it operates differently from Pillar Two and does not meet the OECD's qualifying standards. Over 140 nations have committed to the two-pillar approach, but the US absence creates a real gap because American multinationals are headquartered in the world's largest economy.

To address this, the OECD released a "side-by-side" package on January 5, 2026, intended to address US concerns about the global minimum tax while attempting to preserve its integrity. The package creates a safe harbour that allows US-headed multinational groups to avoid certain top-up taxes applied by other countries, provided the US maintains an eligible tax system. This is a diplomatic compromise, not a full resolution, and the long-term stability of the global framework without full US participation remains an open question.

What About Tax Havens: Are They Finished?

Not entirely, but they are significantly weakened. Countries like Ireland, Luxembourg, Cayman Islands, and Bermuda have historically attracted multinational profits through very low or zero corporate tax rates. Under Pillar Two, the benefit of locating profits in these jurisdictions is dramatically reduced. If a company pays only 9 percent tax in Ireland on certain profits, a top-up of 6 percent will be collected somewhere else. The profit is still in Ireland, but the tax saving has disappeared.

Ireland has responded by introducing its own Qualified Domestic Minimum Top-Up Tax, which means it collects the 6 percent top-up itself rather than letting another country take it. Ireland keeps more revenue, but the company's effective rate still reaches 15 percent. The classic "race to the bottom" on corporate tax rates has, at least for large multinationals, been formally stopped.

What Does This Mean for Indian Businesses?

Indian companies and Indian subsidiaries of foreign groups need to pay attention on two fronts.

First, if an Indian multinational group crosses the 750 million euro revenue threshold and operates in countries that have implemented Pillar Two, those countries can now levy top-up taxes on profits from low-taxed operations. Indian companies with subsidiaries in jurisdictions that currently enjoy tax holidays or special economic zone incentives need to assess whether those incentives survive the Pillar Two framework or whether they will be clawed back through top-up taxes elsewhere.

Second, India has not yet enacted Pillar Two domestically. This means that India is not yet collecting top-up taxes on profits of large foreign multinationals that earn low-taxed income from their Indian operations. Other countries that have implemented the UTPR backstop rule can potentially collect that top-up tax instead, meaning India loses that revenue to other governments. There is a strong fiscal argument for India to implement its own Qualified Domestic Minimum Top-Up Tax, which would allow India to collect that revenue domestically rather than watching it go abroad.

The first GloBE Information Return filings for calendar-year taxpayers were due by June 30, 2026. This means the first wave of Pillar Two compliance reporting is happening right now, and companies that have not yet assessed their exposure are already behind.

The Bottom Line

The global 15 percent minimum tax is not a future policy being debated. It is live law in most of the world's major economies. For any large multinational company, understanding where you stand under Pillar Two is a compliance obligation, not an optional exercise.

For Indian businesses crossing the revenue threshold, for foreign companies with Indian operations, and for advisors working on cross-border transactions, the Pillar Two framework is now a permanent part of the international tax landscape that every deal, every structure, and every tax planning exercise must account for.

This Blog is for general informational purposes and does not constitute legal advice. For guidance on Pillar Two applicability, international tax structuring, or cross-border tax compliance, please contact our team.