The concept of global minimum tax can be traced back to the early 20th century when countries began to recognize the challenges posed by tax avoidance and profit shifting by multinational corporations. The League of Nations, the predecessor to the United Nations, was one of the first international bodies to discuss the need for coordinated action on international taxation.

The idea of a global minimum tax gained momentum in the 1990s and early 2000s, with the Organization for Economic Cooperation and Development (OECD) leading efforts to develop guidelines for international taxation. The OECD's work culminated in the publication of the Base Erosion and Profit Shifting (BEPS) project in 2015, which identified key areas for reform, including the need for a global minimum tax.

In October 2021, the OECD and G20 countries reached a historic agreement on a global minimum tax rate of 15% for multinational corporations. This agreement, known as the "Two-Pillar Solution," aims to ensure that multinational corporations pay a minimum level of tax and to reallocate taxing rights between countries.

The OECD/G20 agreement represents a significant step forward in international tax policy. It is expected to help countries combat tax avoidance and profit shifting by multinational corporations, which have long been a source of contention. The agreement also aims to create a more level playing field for businesses around the world by ensuring that all companies pay their fair share of taxes.

While the OECD/G20 agreement has been widely praised, it is not without its challenges and criticisms. Some critics argue that a 15% minimum tax rate is too low and that it may not effectively deter tax avoidance. Others raise concerns about the complexity of the agreement and its potential impact on small and developing countries.