Federal Supreme Court, 09.07.2026, 9C_399/2026
Facts
After moving from the canton of Zurich to the canton of Aargau in 2019, a taxpayer announced their departure for Vietnam on February 23, 2024. They failed to provide their new foreign address or appoint a representative in Switzerland, despite an explicit request from the tax authorities. Although they filed tax returns for 2023 and 2024, they did not fulfill the obligation to provide a service address. (c. 1.1)
Following the discovery of undeclared income, the Aargau cantonal tax authority issued tax reassessment notices, fines, and procedural costs for the years 2019 to 2021 on September 15, 2025. On November 21, 2025, the tax commission finalized assessments for the 2022, 2023, and 2024 tax periods. Because the taxpayer's whereabouts were unknown, all these decisions were served via publication in the Official Gazette of the canton of Aargau. (c. 1.2, 1.3)
The taxpayer filed an appeal for denial of justice, which was declared inadmissible by the court of first instance. They subsequently appealed to the Cantonal Administrative Court, arguing that the service by publication was void and claiming to have returned to Switzerland in April 2025. The Administrative Court rejected the appeal. The taxpayer then appealed to the Federal Supreme Court, requesting that the service of the notices be declared void and seeking legal aid. (c. 1.4, 1.5, 1.6)
Legal Analysis
The Federal Supreme Court reiterates the requirements for substantiating an appeal in public law matters, in accordance withArt. 42(1) and (2) of the Federal Supreme Court Act (LTF). The appellant must concisely explain how the contested decision violates the law. A heightened duty to provide reasons, pursuant toArt. 106(2) LTF, applies to the violation of fundamental rights, which must be specifically invoked and substantiated. (c. 2.1)
When a taxpayer leaves Switzerland without providing a service address and fails to appoint a representative in Switzerland despite an order from the tax authority, they are considered to have an unknown domicile. In such a situation, serving decisions via publication in the cantonal Official Gazette is a valid form of notification and the only means available to the authority. A taxpayer cannot claim a failure of service if they are responsible for the situation due to their own lack of cooperation. (c. 2.2)
The simplified procedure for dismissal (Art. 108 para. 1 let. b of the Federal Supreme Court Act (LTF)) applies when the appeal brief clearly lacks sufficient reasoning. Furthermore, legal aid (Art. 64 paras. 1-3 LTF) is denied if the appeal's claims appear to have no chance of success from the outset. (c. 2.4, 3)
Application to the specific case
The Federal Supreme Court notes that the appellant merely criticizes the establishment of facts in a general manner, without addressing the reasoning of the lower court. He provides no evidence to contradict the fact that the Aargau authorities only have access to the cantonal register of residents and therefore could not have been aware of his new registration in the canton of Zurich. (c. 2.3)
Crucially, the appellant does not dispute that he was expressly requested to designate a service address or a representative in Switzerland upon his departure abroad, nor that he failed to do so. He also does not claim to have informed the Aargau tax authorities of his return to Switzerland. He is therefore solely responsible for the fact that the authorities considered his domicile unknown and proceeded with service by official publication, which is not void. (c. 2.2, 2.3)
The new evidence submitted by the appellant is deemed inadmissible or irrelevant. The fact that a criminal complaint has been forwarded to a prosecutor in no way prejudges its merits, and an administrative complaint was, in any case, dismissed, confirming the legality of the service by publication. The appeal is therefore clearly insufficiently reasoned. (c. 2.3, 2.4)
Outcome
The Federal Supreme Court declares the appeal inadmissible under the simplified procedure, as it is clearly insufficiently reasoned. The request for legal aid and the appointment of court-appointed counsel is rejected due to the total lack of merit in the appeal. The court costs, set at 800 francs, are charged to the appellant. (c. 1, 2, 3)