Swiss Federal Supreme Court, 08.04.2026, 9C_421/2025
Facts
Upon the termination of their employment in July 2022, A.A.________ received a payment of CHF 253,100 from their employer into their occupational pension account, intended to cover a pension gap.
On August 1, 2022, just a few days after this payment, A.A.________ withdrew a lump-sum benefit from their pension fund totaling CHF 622,747.65. This amount included the CHF 253,100 payment made by the employer.
On September 4, 2023, the tax authority issued a special, separate assessment for the entire withdrawn capital (CHF 622,747.65) at a preferential rate, as provided by law for pension lump-sum benefits. This special assessment decision became final and legally binding (rechtskräftig).
Later, when preparing the ordinary income tax assessment for 2022, the tax authority added the CHF 253,100 amount to the A.________ couple's ordinary taxable income. They justified this decision by arguing that the payment was not a genuine pension benefit but rather a component of salary. However, they announced that they would subsequently correct the special capital assessment through a revision procedure to deduct this amount.
The taxpayers contested this double taxation, but their appeals were rejected by all cantonal authorities, up to the Thurgau Cantonal Court. They subsequently appealed to the Federal Supreme Court.
Legal Analysis
1. Taxation of pension benefits (art. 38 DBRA)
- Lump-sum benefits from a pension institution (such as a pension fund withdrawal) are not taxed as ordinary income.
- They are subject to separate taxation at a reduced rate to ensure the taxpayer is not penalized by the progressive tax scale.
2. Res judicata and revision of a final tax assessment
- A tax assessment that has become final is, in principle, conclusive and cannot be modified.
- Tax law provides an exhaustive list of grounds for revision (e.g., new facts, decisive evidence).
A simple error of law committed by the tax authority during the initial assessment does not, in itself, constitute grounds for revision.
- The authority must bear the consequences of its own procedural or assessment errors.
3. Prohibition of double taxation
- The same item of income cannot be taxed twice for the same tax period for the same taxpayer.
- Taxing an amount both through special taxation (at a reduced rate) and through ordinary taxation (at the full rate) constitutes clear and unlawful double taxation.
Application to the specific case
The Federal Supreme Court ruled entirely in favor of the taxpayers, based on strict procedural reasoning.
Finding of obvious double taxation: The Federal Supreme Court found that the amount of CHF 253,100 had been taxed once as part of the special and final assessment of September 4, 2023, and then a second time in the 2022 ordinary income tax assessment.
- This constitutes "manifest" (offenkundig) double taxation.
Primacy of the final decision: The special capital tax assessment has become legally binding.
It is therefore legally enforceable.
- This final decision precludes the same amount from being taxed again in the ordinary tax assessment procedure.
- Impossibility of revising the special assessment: The Federal Supreme Court ruled that the tax authority could not simply promise to revise its initial decision.
The conditions for a revision are not met.
- The tax authority was fully informed of the facts well before proceeding with the special assessment (the taxpayers had contacted them by email as early as February 2022).
By taxing the capital without thorough examination, the administration committed an error for which it must take responsibility.
- It cannot correct this error to the detriment of the taxpayer in a separate procedure.
- The Federal Supreme Court reiterated its case law (judgment 2C_217/2021) according to which the tax authority must apply the law correctly from the first assessment and cannot revisit a final decision simply because it later proves to be erroneous.
In summary, the final special capital tax assessment "locked in" the tax treatment of the CHF 253,100 amount. It could therefore no longer be included in ordinary income.
Outcome
The Federal Supreme Court has upheld the appeal. The judgment of the Cantonal Court is set aside. The taxpayers' taxable income for the 2022 tax year is reduced by CHF 253,100.
The court costs (CHF 5,000) and legal fees (CHF 4,000) are to be borne by the Canton of Thurgau.
Silex tax newsletter published in collaboration with Anna Vladau, Attorney at Law
