Federal Supreme Court, 28.05.2026, 9C_90/2026
Facts
Following the death of their aunt in 2019, A. and his brother C. were assessed for inheritance tax by the cantons of Vaud and Bern. An initial appeal against the Bernese tax assessment resulted in a Federal Supreme Court ruling on November 2, 2023, which declared A.'s appeal inadmissible but upheld that of his brother C. Based on this ruling, A. initiated new proceedings by requesting a revision of his own Bernese tax assessment. After his request was rejected by the Bernese Tax Administration and subsequently by the Tax Appeals Commission, he appealed to the Administrative Court of the Canton of Bern. (A.a, A.b)
During these new proceedings before the Administrative Court, and following an initial exchange of briefs, A. requested the recusal of the presiding judge, Christophe Tissot, on the grounds that the latter had participated in the cantonal judgment of December 27, 2022, which had been rendered in the first set of proceedings and had been unfavorable to him. By judgment of December 29, 2025, the Administrative Court declared this recusal request inadmissible. A. filed a public law appeal with the Federal Supreme Court against this decision. (A.c, B, C)
Law
The Federal Supreme Court reiterates the guarantee of an independent and impartial judge, as enshrined inArt. 30 para. 1 of the Federal Constitution. This guarantee allows for the recusal of a magistrate when objective circumstances give rise to an appearance of bias and raise concerns regarding impartiality. A party's purely subjective impressions are insufficient. Jurisprudence establishes that a judge's mere participation in prior proceedings involving the same party, even if the decision was unfavorable to them, does not in itself constitute grounds for recusal. (consid. 3.1)
Furthermore, a general principle of procedure dictates that a party who becomes aware of grounds for recusal must invoke them immediately. If the party delays in doing so, despite knowing or having been able to know of these grounds by exercising the required diligence, they forfeit their right to rely on them at a later stage. (consid. 3.2)
Application to the case at hand
The Federal Supreme Court first examines the timeliness of the recusal request. It notes that the appellant became aware of the name of the presiding judge, Christophe Tissot, no later than the notification of a procedural order on October 7, 2025. However, he did not file his recusal request until November 28, 2025, nearly a month and a half later. The Federal Supreme Court deems this delay excessive and considers the request to be untimely. The appellant's argument that he did not pay particular attention to a "purely procedural" order is dismissed. As a party to the proceedings, it was his responsibility to read court communications carefully, and any negligence on his part cannot serve as a justification. (consid. 4.2)
Alternatively, even if the request had not been untimely, the Federal Supreme Court analyzes the merits of the grievance. It confirms the position of the lower court: the fact that Judge Tissot participated in a previous judgment unfavorable to the appellant is not sufficient grounds for recusal under Art. 30 of the Federal Constitution. This conclusion is reinforced by the fact that the two proceedings do not concern the same legal issues. The first proceeding concerned an issue of intercantonal double taxation, whereas the current proceeding concerns a request for the revision of a tax assessment decision. The appellant provided no concrete evidence demonstrating bias on the part of the judge in the new case. The invocation of Art. 9 para. 1 let. b of the Bernese cantonal law (LPJA), which mandates recusal in the event of participation in the "previous decision," is also rejected, as the 2022 cantonal judgment is not the "previous decision" of the current revision proceeding. (consid. 4.3)
In conclusion, the Administrative Court did not violate federal law, and in particular Art. 30 para. 1 of the Federal Constitution, by declaring the recusal request inadmissible due to untimeliness and, furthermore, by considering it unfounded. (consid. 4.4)
Outcome
The Federal Supreme Court dismisses the appeal. The court costs, set at CHF 2,000, are to be borne by the appellant. (consid. 1, 5, 6)
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