TF, 13.10.2026,2C_622/2026
Facts
On May 24, 2023, the competent authority of the United States filed a request for administrative assistance in tax matters with the Federal Tax Administration (FTA) based on Article 26 of the Convention between the United States of America and the Swiss Confederation for the Avoidance of Double Taxation (US-CH DTA) (Fact A).
The request concerned U.S. persons (citizens, residents, or green card holders) who, for federal income tax purposes, had a direct or indirect interest in bank accounts at Bank B.________ AG that met criteria for tax liability without proof of tax compliance ("U.S. Penalty Accounts") between September 23, 2009, and December 31, 2019. These data were transmitted in redacted form by the bank to the U.S. Department of Justice in 2020 as part of a "Plea Agreement" ("Report II.D.2"), and the requesting authority sought the production of the unredacted version (Fact A).
By closing decision dated April 4, 2025, the FTA granted the requested administrative assistance and consented to the transmission of data relating to the bank account in question, subject to the condition that the transmission be accompanied by a notice reiterating the restrictions on use and the confidentiality of the information in accordance withArticle 26, paragraph 2 of the US-CH DTA (Fact B).
Seized by A.________, identified in Report II.D.2 as the beneficial owner of the account, the Federal Administrative Court partially upheld his appeal in a judgment dated September 8, 2026, formally ordering the FTA to notify the requesting authority that the transmitted data may only be used in proceedings directed against the person concerned and for the set of facts described in the request, while dismissing the remainder of the appeal (Facts B.a and B.b).
A.________ (hereinafter: the appellant) filed an appeal in public law matters with the Federal Supreme Court on October 1, 2026, primarily seeking the annulment of the Federal Administrative Court's judgment (except for the clause on usage) and the refusal to entertain or the dismissal of the request for assistance, as well as various subsidiary requests for redaction, the inclusion of a notice of contestation, or the remittal of the case (Fact C).
Law
In matters of international administrative assistance in tax matters, an appeal in public law matters is inadmissible (Art. 83 let. h of the Federal Supreme Court Act (FSCA)), unless a legal question of principle arises or the case is otherwise of particular importance within the meaning of Article 84, paragraph 2 of the Federal Supreme Court Act (FSCA) (Art. 84a of the Federal Supreme Court Act (FSCA)) (consid. 1.1).
The existence of a legal question of principle presupposes a novel or fundamental legal issue whose resolution is likely to guide the practice of lower courts in multiple similar proceedings, provided that this question is decisive for the concrete outcome of the dispute (consid. 1.1).
By virtue of the principle of good faith (Art. 26 of the Vienna Convention on the Law of Treaties), treaty relations in tax matters are based on the principle of trust, according to which the requested State is presumed to rely on the findings and factual declarations transmitted by the requesting authority (consid. 1.2.1).
While it is incumbent upon the requested authority to ensure the foreseeable relevance of the information requested in relation to the foreign tax proceedings, it is not required to verify the intrinsic material accuracy of the facts alleged in the request, as the presumption of good faith can only be rebutted by concrete, proven, and clear evidence (consid. 1.2.1).
This principle applies fully even when the requesting authority relies on information previously provided by a third-party banking institution (consid. 1.2.2).
Application to the specific case
The appellant first raises the question of whether the principle of trust applies when the requesting State adopts, without its own verification, the facts transmitted by a bank (in "Report II.D.2"), arguing that he possesses documents that formally contradict his status as the beneficial owner of the disputed account (consid. 1.2).
The Federal Supreme Court recalls that this exact issue has already been decided in its judgment 2C_234/2025 concerning the same collective request for assistance, in which it was held that the requested State is required to trust the indications in the foreign request, including when these are based on account identifications made by the bank itself (consid. 1.2.2).
As this question has already been clearly addressed by the case law of the Federal Supreme Court, it does not possess any character of novelty or principle (consid. 1.2.2 and 1.2.3).
The appellant then asks for an examination of the scope of the duty of verification and elimination incumbent upon the FTA and the appellate bodies when faced with designations of beneficial owner that are allegedly inaccurate and contradicted by documents (consid. 1.3).
The high Court observes that this criticism amounts solely to challenging the ordinary application of the principle of trust and compliance with foreseeable relevance in the specific case, without stating a general rule justifying an intervention of principle within the meaning of Article 84a FSCA (consid. 1.3).
As the admissibility requirements are clearly not met, the public law appeal is inadmissible from the outset (recital 1.4).
Outcome
The Federal Supreme Court does not consider the public law appeal (operative part 1, recital 1.4).
The court costs, set at 5,000 CHF, are to be borne by the unsuccessful appellant (operative part 2, recital 2).