Executive summary

In December 2025, the Gibraltar Income Tax Office circulated two Guidance Notes: "Pillar Two Registration Requirements in Gibraltar" and "Pillar Two Annual Notification and Gibraltar Top-up Tax Return."

The Guidance Notes provide details on complying with the Global Minimum Tax Act 2024 (the Act), which was enacted on 23 December 2024. For background, see EY Global Tax Alert, Gibraltar's Pillar Two measures, including Qualified Domestic Top-up Tax, now enacted into legislation, dated 3 January 2025.

The Guidance Notes specify the registration requirements and, in the case of certain multinational enterprise (MNE) groups (MNE Groups), provide local Pillar Two returns, as well as additional information on Pillar Two notification requirements in Gibraltar. Further clarification on the processes for submitting registrations, notifications and filing returns is expected in future updates to the Guidance Notes.

Registration

MNE Groups subject to the Act are required to register with the Gibraltar Income Tax Office.

The deadline for registration is 28 February 2026 for MNE Groups with a fiscal year ending between 31 December 2024 and 31 August 2025. MNE Groups with their first Pillar Two fiscal year in Gibraltar ending after 31 August 2025 must register within six months of the end of that fiscal year.

The registration requires the following information:

• Name, registered office address, taxpayer identification number (TIN) and jurisdiction of the Ultimate Parent Entity (UPE)
• Name and Gibraltar taxpayer reference number of the Designated Local Entity (DLE)
• Start and end date for the fiscal year in which the MNE Group or Wholly Domestic Group is first within scope of the Pillar Two Rules in Gibraltar
• Name and TIN for each Gibraltar Constituent Entity
• Information on whether the MNE Group is within scope of the Income Inclusion Rule or the Domestic Top-up Tax in Gibraltar

Once submitted, the Income Tax Office will review the registration form and contact the DLE if any additional information or clarification is required. When the review has been completed, a registration confirmation will be issued to the DLE. The DLE is the Gibraltar Constituent Entity responsible on behalf of the MNE Group for filing the Global anti-Base Erosion (GloBE) Information Return in Gibraltar or, where applicable, for notifying the Commissioner that the GloBE Information Return will be filed in a jurisdiction that has a Qualifying Competent Authority Agreement in effect with Gibraltar.

The Guidance Note also provides information for situations in which, subsequent to registration: (1) a Gibraltar Constituent Entity is added to or removed from an MNE Group; (2) an MNE Group is no longer within the scope of Pillar Two in Gibraltar; or (3) there is a change in DLE.

The Income Tax Office is still finalizing the Pillar Two Registration process.

Gibraltar Top-up Tax Return (Form GMTA1)

An MNE Group subject to the Pillar Two rules in Gibraltar must file Form GMTA1 if, for the relevant fiscal year, it has a Top-up Tax liability in Gibraltar and it is not filing a GloBE Information Return in Gibraltar (because it is filing in a jurisdiction that has a Qualifying Competent Authority Agreement in place with Gibraltar).

The purpose of Form GMTA1 is to allow the tax authorities in Gibraltar to track and reconcile Pillar Two payments. The deadline for filing the Form is the same as for a GloBE Information Return, i.e., 15 months or 18 months after the fiscal year end, as applicable.

Form GMTA1 is intended to be a simple, high-level return, with the information requested limited to:

• Name of the MNE Group
• Name of the DLE
• TIN of the DLE
• Fiscal year for the return
• Amount of the Top-up Tax liability for Gibraltar

Annual notification

As stated in the Act, an MNE Group subject to the Act that files a return in a jurisdiction that has a Qualifying Competent Authority Agreement in place with Gibraltar must file an annual notification rather than a GloBE Information Return in Gibraltar. The notification is due no later than three months before the deadline for the GloBE Information Return.

The Guidance Note states that:

• For entities subject to the Income Inclusion Rule in Gibraltar, the notification may be made by either the UPE or DLE.
• For entities subject to the Domestic Minimum Top-up Tax in Gibraltar, the notification may be made by either a DLE, Domestic Constituent Entity, Domestic Joint Venture or Domestic Joint Venture Subsidiary.
• In either case, the Guidance indicates a preference that the DLE make the notification.

The following information is required to be provided as part of the annual notification:

• Name of the MNE Group
• Start and end date of the fiscal year
• Name, address and TIN for each Gibraltar Constituent Entity
• Confirmation of the DLE and contact details (address, telephone, email and title/capacity) for a representative of the DLE
• Name, address, jurisdiction and TIN of the UPE and confirmation if the GloBE Information Return will be filed in the UPE's jurisdiction
• Details of the Designated Filing Entity (DFE) (only required if the GloBE Information Return will not be filed in the jurisdiction of the DFE)

Information on how to submit a notification will be provided in subsequent guidance.

Implications

The additional requirements for local registration and returns for Pillar Two provided in the Guidance Notes appear to be relatively simple. The clarification on the existing notification requirements is helpful for taxpayers.