At issue is the new global minimum tax regime, based on the mandatory transposition of the European directive, based on the model rules of the Organization for Economic Co-operation and Development (OECD), with the aim of combating aggressive tax planning and trying to provide conditions fair competition for companies globally.

The regime requires groups of multinational companies or large national groups to calculate the effective rate of income tax paid in each of the jurisdictions where the group is present. When this tax is less than 15% (in which case a low-tax jurisdiction is considered to be involved), States may levy a supplementary tax up to this threshold, which will be paid by the parent entity of the economic group.

The 15% rate is a minimum rate, so no State is prevented from applying higher tax rates to profits obtained in its jurisdictions. However, it may lose competitiveness. At the same time, it is also an effective rate, so it is calculated after applying tax benefits and other exemptions or deductions to the income or tax base.

The regime also provides for some transition rules, excluding, for example, situations in which the average revenue of entities in a group is less than 10 million euros and have a net profit of less than one million euros. It also stipulates that large multinationals will escape fines under the minimum 15% taxation regime until fiscal years beginning in 2026 and ending before 2028.

The regime should cover, in Portugal, between 2,700 and 2,800 entities, with the majority being a company whose parent entity is not Portuguese, according to information collected by ECO from a source in the Ministry of Finance.