Portugal Publishes Model 64: Pillar Two Top-up Tax Return

On 30 July 2026, the Portuguese Government published Portaria No. 318/2026/1, approving Model 64 (‘Declaração de Liquidação) RIMG and its accompanying completion instructions. The Ministerial Order entered into force and took effect on 31 July 2026.

Model 64 is a combined local Pillar Two self-assessment return covering top-up tax payable in Portugal under the Portuguese QDMTT, IIR and UTPR.

Background to the Portuguese RIMG

Portugal implemented the EU Pillar Two Directive through Law No. 41/2024 of 8 November 2024, which approved the Regime do Imposto Mínimo Global, or RIMG.

The RIMG incorporates:

-the Income Inclusion Rule, or IIR;

-the Undertaxed Profits Rule, or UTPR; and

-the Portuguese qualified domestic minimum top-up tax, known as the ICNQ-PT.

The regime generally applies to constituent entities located in Portugal that form part of a multinational enterprise group or large domestic group with consolidated annual revenue of at least €750 million in at least two of the four immediately preceding fiscal years. The legislation also contains the usual rules for excluded entities, short fiscal years, mergers and demergers.

The RIMG generally applies to fiscal years beginning on or after 1 January 2024. The UTPR provisions in Articles 8–10 generally apply to fiscal years beginning on or after 1 January 2025, subject to the special rule for groups whose ultimate parent is located in an EU Member State that elected to defer application under Article 50 of the EU Directive.

Article 45(1) of the RIMG establishes three distinct Portuguese reporting obligations:

1. a registration and notification declaration;

2. the information return concerning the top-up tax, corresponding to the GloBE Information Return; and

3. a tax assessment return where a constituent entity calculates top-up tax payable in Portugal.

These obligations have now been implemented through three separate forms:

-Model 62 – the RIMG registration and notification return;

-Model 63 – the Portuguese GIR; and

-Model 64 – the Portuguese top-up tax self-assessment return.

What is Model 64?

Model 64 gives effect to Article 45(1)(c) of the RIMG. It must be used where a constituent entity calculates top-up tax that is payable in Portugal for the relevant fiscal year, and is the top-up tax self-assessment return.

The return covers three possible categories of Portuguese liability:

-ICNQ-PT: Portugal’s qualified domestic minimum top-up tax;

-IIR top-up tax: an amount payable by a Portuguese parent entity in respect of low-taxed constituent entities; and

-UTPR top-up tax: the share of residual top-up tax allocated to Portugal under the UTPR.

Model 64 is therefore a combined return for all three charging mechanisms under the RIMG.

Model 64 v Model 63 

Model 64 should be distinguished from Model 63, which is Portugal’s implementation of the GIR.

Portaria No. 255/2026/1 of 12 June 2026 approved Model 63 and requires the Portuguese GIR to be transmitted electronically as an XML file. The Portuguese Tax Authority subsequently confirmed that the Model 63 submission service is available through the Portal das Finanças under the service name “AEOI-DAC9/GIR”.

Model 63 contains the detailed group, jurisdictional, GloBE calculation and allocation information derived from the OECD GIR. By contrast, Model 64 is a much more focused return. It identifies the relevant taxpayer and group and records the amounts of ICNQ-PT, IIR and UTPR tax payable in Portugal.

Central filing relief for the GIR does not remove the Model 64 obligation. Article 45(2) of the RIMG may relieve a Portuguese constituent entity from filing the GIR locally where the GIR is filed by the UPE or a designated filing entity in a jurisdiction with which Portugal has an effective qualifying competent authority agreement. That relief applies to the information return under Article 45(1)(b); it does not extend to the local tax assessment return under Article 45(1)(c).

Consequently, a group may rely on central GIR filing while still being required to submit Model 64 and pay Portuguese top-up tax.

Who must submit the return?

As a starting point, each in-scope constituent entity located in Portugal must submit Model 64 where it has top-up tax payable in Portugal.

The return must instead be submitted by a designated local entity where the group has appointed such an entity and the appointment has been confirmed in accordance with the Model 62 process. Under Article 45(7) of the RIMG, the designated local entity becomes responsible for filing the tax assessment return for the Portuguese entities that designated it.

The Model 64 instructions accommodate the following filer categories:

-designated local entity;

-constituent entity;

-stateless constituent entity;

-joint venture filing separately; and

-subsidiary of a joint venture filing separately.

Where a constituent entity forms part of more than one in-scope group during the same fiscal year, a separate Model 64 must be submitted for each group.

No nil Model 64 requirement

One of the most important clarifications in the completion instructions is that Model 64 is not required where no top-up tax is payable in Portugal.

The instructions expressly state that where the amount of top-up tax payable in Portugal by one or more relevant entities is zero, there is no obligation to submit Model 64 in respect of that zero liability.

This means that being within the scope of the RIMG does not, by itself, create an annual Model 64 filing obligation. A group may therefore have Portuguese Model 62 and GIR-related obligations but no Model 64 filing where, for example:

-the Portuguese jurisdiction qualifies for an applicable safe harbour;

-the Portuguese GloBE effective tax rate is at least 15%;

-there is no excess profit after the substance-based income exclusion;

-no IIR liability is allocated to a Portuguese parent;

-no UTPR amount is allocated to Portugal; and

-no other additional top-up tax adjustment gives rise to a Portuguese liability.

The zero-return exemption should be distinguished from the €25 collection threshold in the Ministerial Order. Article 4 of Portaria No. 318/2026/1 provides that no collection takes place where the amount assessed is below €25. On the wording of the provisions, a positive assessment below €25 may still require Model 64 even though the resulting amount is not collected, because the filing exemption is expressed by reference to a zero liability rather than an amount below the collection threshold.

Information required in Model 64