September brought significant developments in Portuguese and European taxation, notably in international trade, the implementation of the global minimum tax, corporate capitalisation incentives, VAT and real estate taxation.
In this edition of Highlights, we single out some of the changes, administrative guidance and case law that deserve particular attention for their practical relevance or potential impact on companies, investors and individuals.
European customs reform: the new Union Customs Code is adopted Regulation (EU) 2026/2108 of 16 September established a new Union Customs Code and created the European Union Customs Authority , replacing the regime previously laid down in Regulation (EU) no. 952/2013.
This is a structural reform of the European customs system, designed to adapt customs control and cooperation to the growth of e-commerce, the digitalisation of supply chains and the need for more integrated management of import risks.
For companies engaged in international trade, the reform is expected to have significant consequences for the information to be provided to the authorities, import and export procedures, the management of economic operators and coordination between the customs administrations of the Member States.
Companies with international supply chains should therefore follow the implementation of the new system and assess in advance the impact of the new rules on their customs procedures, IT systems and compliance models.
Pillar Two: the global minimum tax enters an operational phase Implementation of the Global Minimum Tax Regime (Regime do Imposto Mínimo Global , RIMG) continued to progress in September.
In Portugal, the deadline for one of the returns under the regime was extended, and Form 64 – Assessment Return (Modelo 64 – Declaração de Liquidação ) for the 2024 tax year was made available.
At the same time, the OECD published new instruments to make the application of the Pillar Two rules more consistent and predictable, including further administrative guidance on the GloBE Rules and documentation on the legislative assessment of the different jurisdictions.
For in-scope multinational groups, the challenge is gradually shifting from knowing the substantive rules to being able to collect, reconcile and report a significant volume of financial and tax information internationally.
Preparing internal information systems, coordinating across jurisdictions and ensuring consistent data in the top-up tax calculation thus become essential elements of compliance.
VAT: a new arbitral decision challenges the Tax Authority’s position on the pro rata An arbitral decision published in September is of particular relevance to taxpayers with mixed VAT activities.
In Case no. 989/2025-T , the arbitral tribunal ruled on the adjustment of the right to deduct after the final pro rata is determined, and held that the interpretation of Article 23(2) of the VAT Code set out in the Tax Authority’s Circular Letter no. 30108 is unconstitutional, both substantively and formally.
The decision concerns an especially sensitive area for entities that carry out both operations that give a right to deduct and operations that do not, notably financial institutions and other operators with diversified activities.
Although the decision must be read in its procedural context, it reinforces the need to reassess VAT deduction and adjustment methods built solely on the contested administrative interpretation.
Corporate Capitalisation Incentive: new guidance on dividend distributions The Tax Authority again ruled on the Corporate Capitalisation Incentive (Incentivo à Capitalização das Empresas , ICE), clarifying relevant aspects of how it works.
In September, it examined the impact of dividends distributed by a subsidiary when the corresponding profits had already been recognised in earlier tax periods on the calculation of the benefit under Article 43-D of the Tax Benefits Statute.
This adds to earlier guidance on supplementary capital contributions and profit distributions, confirming that applying the ICE requires more than identifying increases in equity in the accounts.
Companies seeking to benefit from the regime should take into account the timing of financing and distribution operations, the origin of the profits and the documentation of changes in equity when setting the group’s financial and tax policy.
Real estate reinvestment: combining a main home and the rental market In September, the Tax Authority continued to give shape to the new exclusion from tax of real estate capital gains linked to increasing the housing supply.
One of the binding rulings expressly considers the case where the proceeds from selling a main home are reinvested in two properties: one as a new main home and the other for the rental market .
The question is particularly relevant because it brings two different reinvestment regimes into a single operation and requires the proceeds to be correctly allocated to the different statutory purposes.
The steady stream of administrative rulings on this matter confirms the importance of structuring sale and reinvestment operations in advance, taking into account the deadlines, the use of the properties and the documentary requirements.
Patronage: the new regime moves into practice After the amendments to the Tax Benefits Statute in August, September brought the regulations needed to put the new patronage regime into operation.
Ordinance no. 437-A/2026/1 of 25 September regulates, among other matters, the registration procedure for beneficiary entities, the award of the cultural entity and cultural initiative designations, the operation of the National Patronage Platform and the related reporting obligations.
The new framework thus leaves its mainly legislative phase and becomes essentially operational.
Entities seeking funding through patronage must now comply with the recognition, registration and reporting procedures. For corporate and individual patrons, properly formalising donations will remain decisive for obtaining the related tax benefits.
Sector levies: new case law on CESE and the banking sector Case law published in September again questioned whether some sector levies comply with the Constitution and with EU law.
In the energy sector, the Central Administrative Court South ruled on the Extraordinary Energy Sector Contribution (Contribuição Extraordinária sobre o Setor Energético , CESE) for 2022 on electricity generation, identifying a constitutional issue.
In the financial sector, decisions were also published on the Banking Sector Contribution (Contribuição sobre o Setor Bancário , CSB) applied to Portuguese branches of institutions based in other Member States, involving freedom of establishment, EU law and substantive constitutional issues.
These decisions confirm that sector levies remain one of the most litigated areas of the Portuguese tax system.
Entities within scope should follow the case law closely, not only for future taxation but also to consider challenging earlier assessments that can still be contested administratively or in court.
