The global minimum tax was designed to ensure that multinational corporations pay at least 15% in every jurisdiction where they operate. Yet recent developments highlight just how contested the rules of implementation remain.

In one recent article, Countries Rework Minimum Tax to Appease US as Concerns Mount (Bloomberg Tax, Sept 8, 2025), the focus is on the pushback from countries like Brazil, India, and EU member states against possible exemptions for US companies. Brazil argued that exempting US-parented groups would be “legally and politically unfeasible,” while India suggested that if flexibility is extended to one, others should receive the same. From this vantage point, the equity and credibility of the system itself could be undermined.

“Carving out only US-parented groups or US companies from the scope of the IIR and UTPR would present significant implementation challenges”

By contrast, a second piece from the Tax Foundation, Side-by-Side Pillar Two Deal a Good Start Toward Tax Simplicity (Sept 9, 2025), frames the carve-out debate differently. It argues that the US already has relatively high corporate taxes (a 21% rate and a 15% domestic minimum) and is not the sort of low-tax jurisdiction that Pillar Two was designed to discipline. From this perspective, exempting high-tax, high-substance countries could actually simplify Pillar Two by avoiding duplicative rules and focusing enforcement on true tax havens.

“The US isn’t the type of troublemaker the UTPR was intended to pursue… Let’s cut to the chase and make things permanent.”

If the Tax Foundation’s reasoning holds, then the effect of a US carve-out may not be as damaging as critics suggest. For example, if a US multinational pays only 5% on profits in a low-tax country, Pillar Two would ordinarily require a “top-up” to 15%. But if the US tax code already claws this back through its own domestic minimum tax and related restrictions, then the global shortfall might already be addressed.

These competing perspectives raise a fundamental question: is Pillar Two primarily about equity, ensuring identical treatment across jurisdictions, or about efficiency, avoiding redundant compliance burdens in high-tax systems? The answer will shape not only how negotiations conclude but also how much tax multinationals ultimately pay in practice.