Property gains: substantial (ATF publication planned) and complex

👉 Taxpayers sell a house to their child at a ‘friendly’ price. ‘Friendly’ because the agreed sale price is 75% of the market value as determined by the tax authorities. How is the capital gain calculated for the purposes of capital gains tax?

The Inheritance and Gift Tax Act (LHID) provides for the deferral of tax in case of a donation. Cantonal law stipulates that in the case of a mixed donation, if the investment cost is lower than the sale price, the deferral of the capital gain on real estate is calculated on the sales portion, with the donation portion deducted.

According to the federal judges, a grammatical analysis leads to the conclusion that the legislator foresaw a «take it or leave it» situation: either there is a gift and everything is deferred, or there is no gift and everything is taxed immediately (para 7.1).

The systematics of the law show two groups of factual situations:
1️⃣ Total reports (all or nothing)
2 partial reports (see 7.2).

The parliament remained silent on the matter. The CF, in the previous version of the legal provision, implied that there should be a complete deferral (recital 7.3).

The purpose of the deferral is to avoid having to pay tax when the money is not available. In the case of a mixed donation, the monetary portion is always lower than the market price: financial inflows are limited (see 7.4).

Federal judges conclude that the legislator intended a deferral in the case of a mixed gift (para. 7.4.3), which is confirmed by the purpose of the law (para. 7.4.4), so there is full deferral of capital gains tax in the case of a mixed gift.

The judgment is in German. It is a case from St. Gallen. A publication in the aTF is planned.

Federal Supreme Court, judgment 9C_271/2025, of 22 December 2025