LAUSANNE - A question that has burdened divorced taxpayers in the canton of Vaud for years is now on the docket of Europe's top rights court. The European Court of Human Rights will have to decide whether Vaud's rules on joint tax liability between former spouses discriminate against women, after the Strasbourg judges accepted an application by the Lausanne lawyer and Green National Councillor Raphaël Mahaim for review.
One application in ten
The admissibility decision is itself a milestone. Only around 10 percent of applications clear that hurdle, and Mahaim described it as a first small interim victory. It is not his first in Strasbourg: in 2024 he helped secure the landmark ruling against Switzerland in the KlimaSeniorinnen climate case, which found that the state had failed to protect older women from the effects of global warming.
What the Vaud rules do
Because married couples are taxed jointly, both spouses are jointly and severally liable for the couple's tax bill. Federal law extinguishes that solidarity when the joint household ends, but cantonal rules differ, and some cantons hold former spouses liable for tax debts from the marriage even after separation. The Federal Supreme Court has found such arrangements compatible with the constitution. In practice, critics say, it is most often women who are pursued for the unpaid taxes of a former husband.
If Mahaim wins on the merits, women in Vaud could have their cases reviewed, and the consequences could reach further. Comparable rules exist in Appenzell and in other European countries, all of which would come under pressure from a Strasbourg judgment. The court will now examine the substance of the case; no date for a ruling has been set. The case lands in a politically sensitive season for Swiss-European legal relations, as Brussels watches Bern's handling of the new treaty package ahead of the National Council's December debate.