Update: extension deadline for filing the domestic top-up tax return (Pillar II)

In an earlier article (Minimum tax for multinationals), we provided an overview of the obligations in Belgium. This clarified that the QDMTT return must be filed on the last day of the eleventh month following the end of the reporting year. For groups with a reporting year ending on 31 December 2024, this means that the first return would have to be filed no later than 30 November 2025.

On 17 November 2025, an important update was announced: the Belgian tax administration is granting an extension for the submission of the first QDMTT return.

Who is eligible for the extension?

Groups whose first reporting year ends between 1 January 2024 and 30 June 2025 are granted an extension until 30 June 2026 to file their QDMTT return.

Please note: this is a one-time extension. For subsequent financial years, the original deadline of eleven months after the end of the financial year remains applicable.

Why an extension?

The final version of the QDMTT return has not yet been published. In this context, the Belgian administration has therefore decided to grant additional time.

The administration’s announcement also states that practical guidelines and technical documentation regarding the filing procedure will be provided at a later date.

Despite the extension, we advise taxpayers to continue with their preparations and start collecting the necessary information to ensure a smooth filing process later on. Groups falling under the permanent or temporary safe harbours must also file a QDMTT return in Belgium.

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