Federal Supreme Court, 02.27.2026, 9C_328/2025
Facts
On December 16, 2018, a taxpayer (the appellant) announced their departure from the municipality of U.________ (Canton of Ticino) to settle in the municipality of V.________ (Canton of Grisons). For the 2018 tax year, they filed their return in Ticino, claiming limited tax liability (economic attachment) based on real estate ownership.
The Ticino tax authority, concluding that the taxpayer's primary tax domicile remained in Ticino, assessed them on the basis of unlimited tax liability for the entire 2018 year. The taxpayer contested this decision, explaining that their move to Grisons was intended to prepare for the relocation of their family (their partner and daughter), who were then residing in a villa owned by the taxpayer in Ticino. Family reunification in Grisons was planned for June 2019, at the end of the daughter's school year.
The taxpayer's objection was rejected, and the tax authority upheld the unlimited tax liability in Ticino. The taxpayer then appealed to the Tax Law Chamber of the Ticino Cantonal Court of Appeal, which in turn confirmed that the tax domicile for 2018 was indeed in Ticino. The taxpayer then filed a public law appeal with the Federal Supreme Court.
Legal Analysis
The Federal Supreme Court reiterated the principles governing the determination of primary tax domicile in cases of intercantonal double taxation.
A natural person has their tax domicile at the place where they reside with the intention of settling there permanently (art. 3 para. 2 LHID). This domicile is determined by the center of personal interests, which is inferred from a set of objective indicators (family, social, professional, and economic ties, etc.). The determining situation is the one that prevails on the last day of the tax period, i.e., December 31 of the year in question. Tax domicile cannot be chosen arbitrarily by the taxpayer.
According to established case law, for taxpayers who are married or living in a domestic partnership, personal and family ties are considered to outweigh professional ties. The primary tax domicile is therefore located at the family's place of residence, even if the taxpayer only stays there on weekends and during their free time (with the exception of senior executives, which does not apply in this case).
Regarding the burden of proof (art. 8 CC), the canton claiming unlimited personal tax liability must establish, with a preponderance of probability, that the taxpayer's center of interests is located within its territory. Failing this, it bears the consequences of the lack of evidence.
Regarding direct federal tax (IFD), the authority to tax generally belongs to the canton of tax domicile. In the event of a dispute over the place of taxation, art. 108 LIFD provides for a specific procedure involving the Federal Tax Administration (FTA).
Application to the case at hand
The dispute concerns whether, as of December 31, 2018, the appellant's center of interests was still located in Ticino, despite his declared departure for Grisons on December 16, 2018.
The Federal Supreme Court conducted a comprehensive assessment of the circumstances and concluded that the Ticino tax authority had provided evidence, with a high degree of probability, that the tax domicile remained in Ticino for the 2018 tax year.
The Court's reasoning is structured around the following points:
- The primacy of the family unit: The Court noted that the appellant, his partner, and their daughter formed a "traditional" family unit. The decision to live together in Grisons had already been made, but its implementation was deferred until June 2019 for schooling reasons.
- The family's place of residence: As of December 31, 2018, the appellant's partner and daughter were still residing in Ticino in a villa owned by the appellant. This residence served as the family's focal point on the critical date. In accordance with case law, the family ties in Ticino were predominant.
- Lack of evidence of an effective transfer: The appellant failed to demonstrate that he had actually transferred his assets and the center of his life to Grisons before the end of the year. The short period between his declared departure (December 16) and the end of the year, which coincided with the holidays, made a complete transfer of his center of interests implausible.
- Maintenance of other ties: The appellant's professional and economic interests also remained primarily anchored in Ticino after his official departure.
- Insufficiency of contrary evidence: The written testimonials provided by the appellant, attesting to his presence in Grisons as of 2018, were deemed too vague and laconic ("...confirms that our acquaintance, A., has lived in V. (GR) since 2018") to be conclusive.
Regarding direct federal tax, the appellant invoked the nullity of the decision due to non-compliance with the procedure under Art. 108 LIFD. The Federal Supreme Court rejected this argument, ruling that, under the circumstances of this case, such an omission did not warrant a sanction as severe as nullity. The confirmation of the tax domicile in Ticino therefore also establishes that canton's jurisdiction for the 2018 direct federal tax assessment.
Outcome
The Federal Supreme Court dismissed the appeal regarding both cantonal taxes and direct federal tax. It upheld the decision of the lower court and established that the appellant's tax domicile for the entire 2018 tax period was in the Canton of Ticino, which is therefore authorized to proceed with his unlimited tax assessment. Legal costs are to be borne by the appellant.
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