Federal Supreme Court, 23.12.2025, 9C_538/2025
Facts
A married couple residing in the canton of Lucerne is challenging their 2020 tax assessment. The husband operates a sole proprietorship based in the canton of Zug. In their tax return, they claimed a self-employment loss of CHF 94,226.
The Lucerne tax authority made several adjustments (notably regarding vehicle and operating equipment depreciation), recognizing a loss of only CHF 28,430, which resulted in a significantly higher income and wealth tax assessment.
Following the failure of their objection and appeal at the cantonal level, the couple has appealed to the Federal Supreme Court. They are requesting the annulment of the Lucerne assessment, the application of the tax factors established by the canton of Zug, and argue that double taxation has occurred. They are also claiming compensation for the alleged excessive duration of the proceedings.
Legal Analysis
- Direct Federal Tax (DFT): The authority to collect DFT from individuals lies with the canton where the taxpayer is domiciled at the end of the tax period (art. 105 para. 1 LIFD). Tax law does not permit dual affiliation (personal in one canton and economic in another) for DFT purposes.
- Cantonal and Municipal Taxes (CMT) and double taxation: Under the Federal Act on the Harmonisation of Direct Taxes (HATA), an individual is subject to unlimited tax liability in their canton of residence and limited tax liability in the canton where they operate a business (art. 3 para. 1 and 4 para. 1 HATA). Each canton involved conducts its own assessment procedure and determines taxable income and wealth according to its own laws.
- The distribution of tax sovereignty between cantons is governed by rules developed by the Federal Supreme Court in application of the prohibition of double taxation (art. 127 para. 3 Cst.). Income from self-employment and the business assets allocated to it are taxable at the location of the business establishment. Double taxation occurs when a person is taxed by two or more cantons for the same tax object during the same period, or when a canton exceeds its tax sovereignty.
Application to the present case
- Direct Federal Tax: As the appellants were domiciled in the canton of Lucerne at the end of the 2020 tax period, this canton has sole jurisdiction to levy the Direct Federal Tax. Furthermore, the canton of Zug did not issue a tax assessment decision for the Direct Federal Tax. The appellants failed to provide sufficiently reasoned objections to the specific adjustments made by the Lucerne authorities to the calculation of the business loss. The appeal is therefore dismissed on this point.
- Cantonal and municipal taxes: The canton of Lucerne, as the canton of domicile, was entitled to conduct its own tax assessment procedure to determine the total taxable income. The appellants' request to assign the tax jurisdiction for the sole proprietorship to the canton of Zug is therefore unfounded.
- Double taxation: The appellants allege double taxation on the grounds that certain assets (vehicles, equipment) were classified as private by Lucerne but as business assets by Zug. The Federal Supreme Court notes that while the Lucerne authorities did indeed refuse to recognize the business nature of certain depreciation (for example, on a new BMW), the assets thus reclassified as private wealth were not subject to wealth tax in the canton of Lucerne. The business assets recognized by Lucerne were correctly allocated to Zug for taxation. The Federal Supreme Court concludes that there is no evidence of actual double taxation of wealth. The differences between the tax assessments of the two cantons are explained by divergences in legislation (e.g., social deductions) and not by double taxation.
- Duration of proceedings: The claim for compensation for excessive duration of proceedings is rejected, as the Federal Supreme Court has already established in a previous decision that there was no culpable delay on the part of the cantonal authority.
Outcome
The Federal Supreme Court dismisses the appeal to the extent that it is admissible. The court costs, amounting to CHF 3,500, are to be borne by the appellants.
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