Luxembourg opens Pillar 2 registration and tax declarations for in-scope entities

On 6 January 2026, Luxembourg officially opened the registration process for entities forming part of a Pillar 2 group. Luxembourg entities within the scope of the Pillar 2 rules as from 1 January 2024 and with a calendar year are now required to register for Pillar 2 purposes by 30 June 2026. Several important elections must be made as part of the registration, including the designation of a filing entity for the GloBE Information Return (GIR). Further, the procedures for the GIR filing (if filed in Luxembourg) and declaration of top-up tax to be paid are now open.

Pillar 2 registration requirements and deadline

All Luxembourg entities forming part of a Pillar 2 group are required to register for Pillar 2 purposes with a dedicated tax office of the Luxembourg Direct Tax Administration (Bureau de Diekirch). This registration should be done entity-by-entity, through an online platform (MyGuichet).

The registration must be completed no later than 15 months after the last day of the group fiscal year for which the group falls within the scope of the Pillar 2 rules or, for the transitional year (i.e., the first year in scope), no later than 18 months after the last day of that fiscal year.

Thus, Luxembourg entities within the scope of the Pillar 2 rules as from 1 January 2024 and with a group calendar year are now required to register for Pillar 2 purposes by 30 June 2026.

Observations

With respect to Luxembourg funds that are in-scope of the rules, even if a fund may not itself be subject to top-up tax, this does not necessarily exclude that the fund may have to comply with certain legal obligations under the Pillar 2 rules, including the registration for Pillar 2 purposes.

Moreover, based on the current rules, a compartment of an umbrella fund is expected to be treated as a separate ‘entity’ for Pillar 2 purposes. Hence, this may require a separate registration.

Information to be disclosed upon registration

As part of the registration, the following information must be provided to the Luxembourg Direct Tax Administration for constituent entities: 

• The identity and tax identification number of the constituent entity;
• The name of the multinational enterprise (MNE) group or large-scale domestic group;
• The identity of the ultimate parent entity (UPE) and the jurisdiction where it is located;
• The fiscal year for which the group falls within the scope of the Pillar 2 rules;
• The fiscal year during which the entity joined the group if that fiscal year is posterior to the fiscal year in which the group came under the scope of the Pillar 2 law;
• The date on which the fiscal year of the group ends;
• The identity of the designated local filing entity (if applicable);
• The identity of the designated group filing entity (if applicable);
• The identity of the designated paying entity (umbrella entity) for the purposes of the Undertaxed Profits Rule (UTPR) tax (if applicable);
• The identity of the designated paying entity (umbrella entity) for the purposes of the Qualified Domestic Minimum Top-up Tax QDMTT (if applicable);
• Name and contact details of the relevant individual with respect to the registration

Luxembourg joint venture entities as per the Pillar 2 rules and Luxembourg joint venture subsidiaries are also expected to register for Pillar 2 purposes. The information is broadly similar as mentioned above.

Observations

The registration process allows groups to make certain elections, such as designating a filing entity for the GIR. When selecting a group filing entity, it is essential to consider whether the chosen jurisdiction has implemented Pillar 2 rules, participates in automatic information exchange (e.g., under DAC 9 or the OECD Multilateral Competent Authority Agreement, MCAA), and provides adequate safeguards for information dissemination.

Luxembourg has aligned with international standards leveraging both DAC 9 and the MCAA for information exchange. In this context, Luxembourg offers a simplified and efficient framework for multinational groups with a local presence to comply with the Pillar 2 group requirements.

Deregistration process and changes to the registration information

In-scope entities that fall outside of the Pillar 2 rules in a subsequent year or cease to be an entity of the group should deregister for Pillar 2 purposes. Similarly, in case information with respect to the registration changes (e.g. migration of an entity or change of filing entity), a notification is to be submitted.

The deregistration must be completed no later than 15 months after the last day of the group fiscal year for which the group is no longer subject to the Pillar 2 rules, or the entity ceases to be part of a Pillar 2 group. The same deadline applies in case of notifications that would amend the registration information.

Observations

In-scope Luxembourg entities dissolved during fiscal year 2024 are still expected to be registered for Pillar 2 purposes. Information is to be shared with respect to the  entity liquidation while registering the entity.

Penalties

As per the Luxembourg Pillar 2 Law, a lump-sum fine of EUR 5,000 may be imposed on any Luxembourg constituent entity which fails to register or deregister within the deadline or transmits incomplete or incorrect information in the registration / deregistration forms.

Tax declarations

Luxembourg also published the procedures to file the GloBE Information Return (GIR) and to declare any top-up tax in Luxembourg (QDMTT, IIR, UTPR).

With respect to the GIR, groups have the possibility to file in Luxembourg or in a foreign jurisdiction (subject to exchange of information conditions). The top-up tax declaration is a self-declaration of additional top-up tax to be paid by Luxembourg entities. The top-up tax declaration is expected to be filed by parent entities for IIR purposes, as well as designated umbrella entities for QDMTT and UTPR purposes. In the latter case, if no designation has been made, the top-up tax return could be due by several Luxembourg entities to which top-up tax is to be allocated. If no additional tax is due, the declaration is still expected to be filed (nil filings would be due).

The first Pillar 2 compliance requirement for Luxembourg entities is opened with deadline on 30 June 2026 for calendar year groups in scope since 1 January 2024.

Groups must carefully consider elections that can be made during the registration process, such as the choice of a designated filing entity or designated paying entity for QDMTT and UTPR.

Failure to comply with registration, deregistration or notification requirements may result in a lump-sum fine of EUR 5,000 per infringement.

For those navigating the complexities of Pillar 2, tailored training and support, such as PwC's Pillar 2 Training Programme, can help ensure your teams are prepared and compliant.