On 9 July 2025, the Portuguese Official Gazette published Supreme Administrative Court (“Court”) Judgment 8/2025, which ruled in favor of a Luxembourgish undertaking for collective investment in transferable securities (UCITS) (“Claimant”).
The Court established that whenever national tax provisions are set aside due to incompatibility with European Union law, taxpayers are entitled not only to a refund of the unduly withheld tax but also to indemnity interest at a yearly rate of 4%. This interest accrues from the date of the express or tacit rejection of the administrative claim filed against the undue withholding of taxes at source.
This Judgment was issued following an appeal lodged by the Claimant against an arbitration ruling. While the Arbitration Court acknowledged that the Portuguese tax framework on dividends paid to non-resident investment funds breaches the free movement of capital, it only sentenced the Portuguese tax authorities to interest from the date on which the arbitration ruling became final and unappealable.
The Judgment further clarifies previous inconsistencies in arbitral and judicial decisions regarding the starting point for the calculation of indemnity interest. This Judgment aligns Portuguese procedures with EU law requirements, ensuring effective restitution and non-discriminatory treatment for non-resident taxpayers.