Does the procedure allow for a win?

The taxpayer is a self-employed lawyer living in one canton and working in the neighbouring canton. As they did not file their return on time, they were assessed by default. The taxpayer lodges a complaint within the time limit, then completes their complaint by filing their tax return.

The tax office processes the claim but refuses a particular deduction. The file is passed on to superiors. The superiors refuse to process the claim, stating that the claim was not regular. Indeed, against an official assessment, the claim must prove that the official assessment is manifestly inaccurate and therefore produce all means of proof to determine the taxable elements. However, the taxpayer produced these elements out of time.

The cantonal judges find that the taxpayer did not prove in their claim (the one filed within the deadline) that the ex officio assessment was manifestly inaccurate. Consequently, the ex officio assessment became res judicata.

Federal judges have removed a letter from the tax authorities from the case file. This letter is an assessment that «cancels and replaces» the default assessment. According to the federal judges, the tax authorities therefore considered the claim to be valid. The tax authorities' hierarchy cannot question the actions of their subordinates without acting in bad faith.

Consequently, the tax authority's hierarchy acted in bad faith and the case must be returned to the tax authority for a decision on the disputed deduction.

The ruling is in French. This is a Vaudois case.

Federal Supreme Court, judgment 9C_36/2025, of 1 July 2025