Portugal has taken a decisive step in implementing the international minimum taxation rules through the introduction of the Global Minimum Tax Regime (GMTR), internationally known as the OECD Pillar Two framework. This new tax framework aims to ensure that large multinational and domestic groups pay a minimum effective tax rate of 15% in every jurisdiction where they operate.
With the first reporting deadlines approaching and the recent publication of guidance regarding the complementary tax information return (GIR), affected companies are facing new tax compliance, reporting and international coordination requirements. In this article, we explain what is at stake, who falls within the scope of the regime, the main obligations involved and the key considerations for businesses operating in Portugal.
Portugal has officially implemented the Global Minimum Tax Regime (GMTR) through the transposition of the European Directive relating to the OECD Pillar Two rules. This regime represents one of the most significant transformations in international taxation in recent decades and introduces a new paradigm for the taxation of large corporate groups.
The primary objective of Pillar Two is to combat base erosion and the artificial shifting of profits to low-tax jurisdictions. In practice, the rules are designed to ensure that in-scope groups pay a minimum effective tax rate of 15% on profits generated in each country where they operate.
Who is covered by the GMTR?
As a general rule, the regime applies to:
- Large multinational groups;
- Large domestic groups;
- Groups with annual consolidated revenues of at least €750 million in at least two of the previous four financial years.
This means that many Portuguese companies forming part of international groups may become subject to new reporting obligations, even where no additional tax is payable in Portugal.
What changes in practice?
Pillar Two introduces a complex set of mechanisms for calculating the effective tax rate on a jurisdiction-by-jurisdiction basis. Whenever that rate falls below 15%, a supplementary tax (“top-up tax”) may become payable.
In addition to the tax calculation itself, businesses will now face new administrative obligations, including:
- Registration of in-scope entities;
- Submission of the Model 62 return;
- Filing of the GIR (GloBE Information Return);
- International exchange of information between tax authorities.
These obligations require close coordination between finance, tax, legal and international teams within corporate groups.
GIR return: a new international reporting obligation
International guidance has recently been issued regarding the filing of the complementary tax information return, known as the GIR. This return plays a central role in the operation of Pillar Two, enabling tax authorities to exchange information concerning the calculations performed by affected groups.
A common understanding has also been established between participating jurisdictions, including Portugal, in order to facilitate the centralised filing of the GIR and minimise operational issues relating to electronic platforms and information exchange mechanisms.
In practice, where the GIR is centrally filed in an eligible jurisdiction, local tax authorities may waive certain penalties associated with reporting failures, provided that specific conditions and notification requirements are met within the legal deadlines.
Model 62: attention to deadlines and reported information
In Portugal, the Model 62 return is particularly relevant within the scope of the GMTR. This return is intended for the registration of in-scope entities and for identifying the jurisdiction where the GIR will be submitted.
Companies should carefully verify:
- Whether the mandatory registration has already been completed;
- Whether the jurisdiction indicated for the GIR filing remains valid;
- Whether a replacement return needs to be submitted;
- Whether local entity designation procedures have been properly fulfilled.
The Portuguese Tax Authority has also clarified specific procedures relating to amendments to Model 62 and designation confirmation mechanisms.
A new tax compliance challenge
The GMTR represents far more than a new tax obligation. It is a structural change in the way multinational groups monitor their global taxation.
Affected businesses will need to ensure:
- Consistent collection of international financial information;
- Harmonisation of accounting and tax criteria;
- Review of corporate structures;
- Assessment of existing tax incentives;
- Continuous monitoring of the effective tax rate in each jurisdiction.
Furthermore, the technical complexity of the regime requires specialist support and early preparation in order to avoid non-compliance, penalties and reputational risks.
Conclusion
The Global Minimum Tax Regime (GMTR/Pillar Two) marks a new era in international taxation in Portugal. Although its purpose is to promote greater tax fairness and reduce aggressive tax planning practices, the operational and reporting impact on corporate groups will be substantial.
Implementing these rules requires technical preparation, strategic analysis and an integrated approach involving tax, accounting and international reporting functions. The coming months will be critical for many companies, particularly in meeting the first reporting obligations and adapting to the new mechanisms for global tax information exchange.
How can Nominaurea help?
Nominaurea supports domestic companies and international groups in adapting to the new Global Minimum Tax Regime (GMTR/Pillar Two), providing specialist assistance in:
- Assessing whether the regime applies;
- Reviewing reporting obligations;
- Supporting the completion of Model 62;
- Assisting with the GIR return;
- Evaluating international tax impacts;
- Tax and accounting compliance;
- Coordination with international teams and audit processes.
In an increasingly demanding and globalised tax environment, specialist technical support is essential to ensure compliance, reduce risks and maintain efficient tax management.
