In a judgment handed down on 17 June 2026, the Commercial Chamber of the Court of Cassation clarified that the tax authorities cannot rely on the absence of a note in the margin of the marriage certificate regarding a duly effected amendment to the matrimonial regime in order to set aside its effects.

In this case, spouses had amended their marriage contract to include a preciput clause (a clause allowing the surviving spouse to take certain community assets before the estate is divided). Two years later, the wife passed away, leaving behind her husband, their three children, and three grandchildren. After the inheritance tax return had been filed, the tax authorities issued a reassessment notice and added back into the taxable estate the surrender value of two life insurance policies that had been transferred to the surviving spouse pursuant to the preciput clause. The corresponding inheritance tax was subsequently assessed.

After their administrative appeal was rejected, the heirs brought proceedings against the tax authorities seeking relief from the additional inheritance tax, together with the related interest and penalties.

The Court of Appeal dismissed their claim, holding in particular that the tax authorities, acting on behalf of the State, should be regarded as a third party within the meaning of Article 1397 of the French Civil Code. It therefore concluded that the amendment to the matrimonial property regime was not enforceable against the tax authorities because it had not yet been recorded in the margin of the marriage certificate.

In its decision, the Court of Cassation held that, pursuant to Articles 720 and 1397 of the French Civil Code and Article 750 ter of the French General Tax Code, “where spouses have validly amended their matrimonial property regime to include a preciput clause, withdrawals made by the surviving spouse from the community property under that clause must be taken into account in determining the composition of the deceased’s estate for the purpose of assessing inheritance tax, regardless of the date on which the amendment was recorded in the margin of the marriage certificate.”

Implicitly, the Court of Cassation ruled that the State is not a third party for the purposes of Article 1397 and that the amendment to the matrimonial property regime is enforceable against the tax authorities regardless of when it was recorded in the margin of the marriage certificate. The Court quashed the Court of Appeal’s decision, expressly criticizing its reasoning that the State should be regarded as a third party.

Accordingly, the Court reaffirmed that the amendment to the matrimonial property regime was fully enforceable against the tax authorities, which were required to take it into account when determining the taxable estate.

This ruling reinforces the principle that taxation must reflect the parties’ actual legal situation, reaffirming the objective nature of French tax law.