The Swiss authorities online
If you sell your house at a profit, the capital gain is taxable.
Private owners often make a profit when selling a house or a piece of land. All cantons tax these profits: in most cases, these taxes are levied by the cantons themselves, while in some cantons they are also levied by the communes. In the cantons of Zug and Zurich, it is only the communes that levy these taxes.
The Confederation does not tax profits made from the private sale of land.
The seller pays the tax, not the buyer. The amount usually depends on the amount of profit from the sale and on the period of ownership.
If you decide to use the capital gain to purchase a new home, you will pay less property gains tax, or none at all. The amount depends on how much of the capital gain you invest in the new property.
The tax office calculates the tax. The original purchase price is deducted from the profit you make on the sale. Other deductions also apply.
In most cantons, a property transfer tax is charged as well as property gains tax.
In which canton is your property located? Please contact the tax office in that canton.