Federal Supreme Court, 24.10.2025, 9C_210/2025
Facts
Taxpayers were assessed for the 2022 tax period by a decision dated December 19, 2023, which established the tax value and rental value of their property. This decision became final. On May 22, 2024, a new official valuation of the property, following new construction, resulted in lower values. The taxpayers then requested a revision and rectification of the 2022 assessment, based on this new valuation and requesting that the rental value be calculated only for a period of four and a half months. Their request was rejected by the tax authority and subsequently by the Obergericht of the canton of Appenzell Ausserrhoden. The taxpayers appealed to the Federal Supreme Court.
Legal Analysis
The Federal Supreme Court reiterates that final tax assessments can only be challenged through extraordinary legal remedies, the grounds for which are exhaustively listed by law (numerus clausus). In this case, these are revision and rectification.
Revision (Art. 51 LHID; Art. 189 StG/AR) allows for the correction of a decision based on an erroneous or incomplete set of facts. It may be requested, in particular, when significant facts or conclusive evidence are discovered. However, revision is excluded if the applicant invokes elements that they could have raised during the ordinary proceedings by exercising due diligence.
Rectification (Art. 52 LHID; Art. 192 StG/AR) is intended to correct clerical errors (calculation or transcription errors). It applies only to errors in the expression of the authority's intent ("Handarbeit"), such as a typo, and not to errors in the formation of that intent ("Kopfarbeit"), which involve erroneous legal or factual assessment.
Application to the case
The Federal Supreme Court examines whether the conditions for revision or rectification are met.
Regarding revision, the taxpayers argue that the new 2024 property valuation constitutes a significant new fact. The Federal Supreme Court rejects this argument. The cantonal tax law (Art. 47 para. 2 StG/AR) provides for a specific valuation method for new constructions pending an official valuation. The initial assessment was therefore not flawed from the outset. Furthermore, a valuation, by its nature, involves a margin of imprecision and generally does not constitute a new fact within the meaning of revision law. If the taxpayers contested the initial calculation method, they should have done so through an ordinary appeal.
Regarding rectification, the taxpayers invoke two clerical errors: the inclusion of the rental value for the entire year 2022 instead of a pro-rated period, and the method of calculating the tax value. The Federal Supreme Court also dismisses these arguments. The decision to tax the rental value on an annual basis, even if potentially substantively incorrect, constitutes an error of judgment (formation of intent) by the tax authority and not a simple clerical error (expression of intent). Similarly, the method of calculating the tax value, explicitly mentioned in the tax assessment, is the result of the authority's decision-making process. It is neither a calculation error nor a transcription error.
As the conditions for revision or rectification are not met, the tax authority's refusal to revisit the final assessment is upheld.
Outcome
The Federal Supreme Court dismisses the taxpayers' appeal and orders them to pay the legal costs.
Silex Tax Newsletter published in collaboration with Anna Vladau, Attorney at Law
