The Organisation for Economic Cooperation and Development said the fresh package preserves the 15 per cent global minimum tax framework designed to ensure large multinationals pay a baseline tax wherever they operate.
The update includes simplifications and carve-outs to align US minimum tax laws with global standards, accommodating earlier objections raised by US President Donald Trump's administration.
OECD's Australian head Mathias Cormann said in a statement the arrangement "enhances tax certainty, reduces complexity and protects tax bases".
US President Donald Trump declared in an executive order when he took office nearly a year ago that the OECD global minimum tax deal would have "no force or effect" for the US.
Treasury Secretary Scott Bessent said Monday's agreement would ensure that US-headquartered companies would only be subject to US global minimum taxes and preserve benefits of US research and investment tax credits.
"This agreement represents a historic victory in preserving US sovereignty and protecting American workers and businesses from extraterritorial overreach," Bessent said in a statement.
He pledged to continue engagement with other countries on a "constructive dialogue" on taxation of the digital economy, a reference to a second, more difficult pillar of the OECD tax framework.
As of October, more than 65 countries had begun implementing the 2021 global tax deal, which requires them to apply a 15 per cent corporate tax or impose a top-up levy on multinationals booking profits in jurisdictions with lower tax rates.
The revised agreement solidifies global backing after G7 countries, including the US, brokered a deal in June exempting some US companies from parts of the original framework.
A broader agreement, reached on Monday after the US pressured holdouts to back the updated arrangement, helps stabilise the global deal.
