Swiss Federal Supreme Court, 03.13.2026, 9C_567/2025
Facts
A married couple with one child, originally domiciled in the canton of Ticino (TI), is at the center of a double taxation dispute with the canton of Grisons (GR) for the 2017 and 2018 tax years. The husband had transferred his civil domicile to Grisons in 2014, while his wife and daughter joined him in July 2017.
For the years 2015 and 2016, the two cantons had agreed on an ad hoc split of taxable items at 50% each. During the years in dispute (2017-2018), although officially domiciled in Grisons, the family maintained close ties to Ticino: the husband was employed by a Ticino-based company, the wife worked part-time in Ticino and managed a limited liability company there, and their daughter attended a private school in Ticino. The taxpayer maintained that he resided in Ticino during the week for professional reasons and spent weekends and holidays in Grisons.
The Ticino tax authorities, considering that the family's center of interests was located within their territory, proceeded with ex officio assessments for 2017 and 2018. The taxpayer contested this unlimited tax liability in Ticino, citing his Grisons domicile and the existence of final tax assessments from that canton. After lengthy cantonal proceedings, the Ticino Court of Appeal confirmed Ticino's tax jurisdiction. The taxpayer appealed to the Federal Supreme Court, alleging a violation of the prohibition on double taxation, the statute of limitations on the right to tax, and the principle of good faith.
Law
The Federal Supreme Court reiterates the principles governing the determination of tax domicile in cases of intercantonal double taxation (Art. 127 para. 3 of the Federal Constitution). An individual's tax domicile is located where they reside with the intention of establishing themselves permanently, which corresponds to the center of their vital interests. This concept is determined based on an objective assessment of all circumstances (family, professional, social, and economic ties), rather than the taxpayer's declarations or wishes. The situation at the end of the tax period (December 31) is decisive. The canton claiming tax jurisdiction must prove with a preponderance of probability that the taxpayer's center of interests is located within its territory.
The Federal Supreme Court also examines the issue of the statute of limitations on the right to tax. In accordance with harmonized tax law (Art. 47 LHID) and Ticino law (Art. 193 LT/TI), the right to tax expires five years after the end of the tax period (relative statute of limitations) and, in any case, after fifteen years (absolute statute of limitations). The relative statute of limitations can be interrupted (e.g., by a tax assessment) or suspended (e.g., during appeal proceedings), which triggers new time limits.
Finally, the Court addresses the principle of protection of good faith and legitimate expectations (Art. 9 of the Federal Constitution). For a taxpayer to rely on this principle, they must have received specific and explicit assurances from a competent authority, upon which they relied to their detriment. The mere fact of having benefited from a certain tax treatment in previous years does not create a vested right to have that treatment maintained in the future.
Application to the specific case
The Federal Supreme Court addresses the appellant's grievances in turn.
First, regarding the statute of limitations, the Court rejects the taxpayer's argument. The absolute limitation period of fifteen years has clearly not been reached. As for the relative limitation period of five years, it was validly and repeatedly interrupted and suspended by the various tax assessments, objections, and appeal proceedings initiated by the Ticino authorities. The Canton of Ticino's right to tax is therefore not time-barred.
Second, and this is the core of the ruling, the Federal Supreme Court confirms the lower court's analysis that the family's center of vital interests was located in Ticino during 2017 and 2018. It bases its conclusion on a set of consistent indicators:
- Professional ties: The husband's primary gainful activity and the wife's activity (as an employee and manager of her own company) were carried out in Ticino.
- Family and social ties: The couple's daughter was enrolled in school in Ticino, and family life during the week took place in that canton.
- Economic ties: The couple's primary banking relationships, including those for significant mortgage loans, were established with Ticino institutions.
In light of these overriding factors, the ties to Grisons (civil domicile, ownership of real estate, leisure activities on weekends) appear secondary and are insufficient to establish the center of vital interests there. The Court emphasizes that the declared civil domicile is not decisive when faced with the objective reality of the facts.
Third, the Court dismisses the argument based on good faith and the 50/50 allocation agreement for 2015-2016. It finds that the appellant received no explicit assurance from the Ticino authorities that this agreement would be renewed for 2017 and 2018. Furthermore, the written communications provided show that this agreement was transitional in nature and that even the Grisons authorities linked it to the situation prior to the wife and daughter's relocation. The past agreement could not, therefore, form the basis for legitimate expectations for subsequent tax periods.
Outcome
The Federal Supreme Court rules as follows:
- The appeal against the Canton of Ticino is dismissed. The unlimited tax liability of the taxpayer and his spouse in Ticino for cantonal taxes and direct federal tax for the years 2017 and 2018 is confirmed.
- The appeal against the Canton of Grisons is upheld. The tax assessments issued by the Grisons authorities for the same periods are annulled.
- The Canton of Grisons is ordered to refund the taxes unduly collected. The cantonal portion will be transferred to the Canton of Ticino and the federal portion to the Confederation. The Canton of Ticino will proceed with the final settlement with the taxpayer.
- The appellant's request for legal aid is denied. Court costs are to be borne half by the appellant and half by the Canton of Grisons.
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