Belgian Constitutional Court Decision in the UTPR-case

The Belgian Constitutional Court (BCC) issued a decision in the so-called “UTPR-case” on 24 September 2026 (see: 2026-0107n). The appeal in this case was filed by the American Free Enterprise Chamber of Commerce, a non-profit organization under the law of the State of Wyoming (United States), which requested the annulment of the UTPR provisions of the Belgian Law on minimum taxation (i.e., Articles 35-36 of the Law).

The BCC has now decided that the envisaged transaposition of the Side-by-Side package into Belgian legislation has no impact on the continuation of the proceedings pending before the BCC.

Following the appeal, the BCC submitted a question for preliminary ruling to the Court of Justice of the EU in July 2025 (see: C-519/25 - American Free Enterprise Chamber of Commerce). The BCC asked whether Articles 12 to 14 of the Council Directive 2022/2523 of 14 december 2022 infringe various European rights and legal principles, insofar as those provisions require Member States to subject constituent entities of an MNE group established in the EU to a UTPR top-up tax, and to make these entities liable for paying tax on undertaxed profits of other group entities established in another jurisdiction, without any distinction being made according to the financial capacity of those taxable constituent entities. For more information, see our previous news item: Belgian Constitutional Court raises prejudicial question about the UTPR.

Subsequently, the Court of Justice of the EU requested information from the BCC to determine whether the envisaged measures of the Side-by-Side package of 5 January 2026 have an impact on the appeal. 

 The implementation of the OECD’s Side‑by‑Side package in the context of Directive 2022/2523 was confirmed by the European Commission in Commission Notice C/2026/253 of 12 January 2026. To date, the envisaged measures have not been transposed into Belgian law. The BCC concludes that the mere fact that a draft law to that effect is in preparation is not sufficient to deprive the applicant of its interest in seeking the annulment of the contested UTPR provisions.

Moreover, the BCC also argues, that even if the Side‑by‑Side safe harbour were transposed into Belgian law, it would only apply where the UPE’s jurisdiction meets the relevant criteria, such as the US jurisdiction. Consequently, a Belgian subsidiary of a US company whose UPE is not established in a jurisdiction that meets the criteria would not be able to benefit from the Side‑by‑Side safe harbour and could be liable for the UTPR top‑up tax. Furthermore, it cannot be ruled out that Belgian subsidiaries of US companies may be liable for a UTPR top‑up tax for the fiscal year 2025.

As a result, the contested provisions can still affect the interests of US companies, and the envisaged measures following the Commission Notice C/2026/253 therefore have no impact on the continuation of the proceedings pending before the BCC.

The BCC’s decision means that the proceedings continue and that the Court of Justice of the European Union is expected to answer the question for a preliminary ruling raised by the BCC. The outcome of the case might have a pivotal impact on the UTPR top-up up tax, which serves as a backstop mechanism within the global minimum taxation framework. However, the outcome of the case remains difficult to predict.

If you have any questions concerning the above or require assistance with the Belgian minimum tax, please do not hesitate to contact your trusted KPMG advisor or reach out to us directly.