Almost a century from its foundation, the international tax regime intended as a set of principles and rules governing cross-border income taxation is on the brink of unprecedented change. Due to the evolution in the ways MNEs conduct their business, on the one hand, and the proliferation of aggressive tax planning schemes and excessive tax competition, on the other, on 8 October 2021 more than 130 jurisdictions participating in the OECD Inclusive Framework have agreed to the OECD Two-Pillar Solution to address the tax challenges of the digital economy. Indicatively, the OECD Pillar One aims at reallocating taxing rights among countries by means of a new connecting factor (or nexus) based on the role that markets play in the modern economic context (hereby seeking to keep up with the evolution of digital companies’ business models). The approach of allocating taxing powers to states relying on the physical presence criterion [ permanent establishment] has become anachronistic given the possibility for (digital) companies to derive profits in a jurisdiction without tangible production factors located therein. The OECD Pillar Two, instead, introduces a 15% minimum global taxation to limit excessive tax competition among states and purports to promote a better allocation of investments at the global level, ideally enlarging residence states’ taxing powers. Noticeably, the second pillar also represents a major step forward in terms of harmonizing the computation of corporate taxable base. This contribution, after shortly describing the fundamental notions of international tax law from an international public law angle, traces the crucial steps that eventually led to the 2021 reform and presents an overview of the functioning of both the OECD Pillars.