In the case of partial donations, the tax is not due until a later date

Anyone who sells a house at a profit must pay capital gains tax. However, if the property is gifted, either in full or in part, this tax can be deferred. The Federal Supreme Court has now confirmed that even in the case of a mixed donation – for example, a sale to one’s own children at below market value – the tax may not be levied on a pro rata basis. It becomes payable in full only when the recipients subsequently resell the house and is calculated on the basis of the total increase in value since the parents’ original purchase.

Practical implications:

A couple from St. Gallen sold their house to their son at a reduced price. The canton sought to collect part of the capital gains tax immediately. However, the Federal Supreme Court ruled in favour of the parents: the tax is deferred in full until the son resells the property. This can be advantageous for families if the property remains in the family in the long term. However, the offspring faces a higher tax burden later on, particularly if they sell the house relatively soon.

Nationwide significance:

The ruling applies to all cantons. Among those affected are St. Gallen, Basel-Landschaft, Bern, Lucerne and Vaud, which must now adapt their practices. (Source: BGE 9C_271/2025 of 22 December 2025)