Pillar Two is also the closest to coming into effect, notably in the European Union, where countries agreed in December on a directive for harmonized implementation starting at the end of this year.
The other part of the overhaul, known as Pillar One, is designed to share taxing rights more fairly between jurisdictions after many European governments complained that US tech firms are generating huge revenues in their countries while paying little tax.
If implemented, the OECD now estimates the new rules would reallocate taxing rights on $200 billion of profits instead of $125 billion in its previous assessment.
The net boost to annual global tax revenues under Pillar One would be much smaller, at around $13 billion to $36 billion.
Negotiations on technical details are also moving more slowly, with the aim of agreeing a multilateral convention that countries could begin signing from mid-2023.
The OECD gave more detail on which companies would be impacted by the reallocation of their profits for tax purposes:
- Around 50% of the $200 billion would come from large digital companies
- Rest would come from other sectors, notably pharmaceuticals and consumer goods
The OECD also sought to respond to some developing economies that have criticized the overhaul for not sharing a sufficient proportion of taxing rights. According to the analysis of the latest version of the rules, low and middle-income countries would gain the most as a share of existing corporate tax revenues.
“The significant increases in revenue gains published by the OECD highlight the importance of swift implementation of both pillars for all countries,” it said.