Property abroad is entered into your Swiss tax return as an asset so it will cause your proportionate wealth tax to increase, but its just like any other asset really from that perspective. Typically you wouldnt pay income taxes in Switzerland on property abroad ( if you rent it out for example ) because ordinarily the other country is already taxing you on that. 

Thanks for your reply. However what I am looking for is what paperwork is needed. For example, how on earth do you prove to the tax authorities that you do not rent out your property? I have asked both my bank and commune in Spain and neither know how to do this! I thought that someone who has already gone down this road might have some advice?

They don't ask for proof that you don't rent it out. On the other hand they ask for an estimated rental value that you will get taxed on even if it is not rented out. That does not make sense but the rental value of your property is added to your general income and then taxed. The rental value could come from the tax documents from the country where you have the property or you can ask a rental agency to provide you with the rental amount. It does not make sense at all, but this is the way I understand the system.

Can only speak about property in england.  You declare the actual purchase price and the date of purchase and you are taxed on the purchase price, not today's value.  This price is then reduced in stages of 10% to a minimum of 60% of the value (cannot remember when this starts kicking in or whether it is 10% per year or 10% every 5 years.  So if you bought a property at 100'000 francs 20 or 30 years ago you would be taxed on a value of 60'000 francs.  What I am not sure about is that if you sell it for 1'000'000 francs, whether you are taxed on the profit.

Would be interested to know.

Regarding rentable value, everything said above is true but have never been able to work it out.  I know the tax authorities always correct whatever figure I present.

You can also claim for things like service charges but not commune (in England council taxes)Also invoices for repairs are tax deductible

To Paul:  If you own a property abroad, move here and sell it at a later date then the Geneva authorities dont tax you on the capital gain but the country where the property exists may.  In the UK as an example capital gains tax on residential property didnt use to be charged if you had lived away from the country for over 5 years but the law changed in 2015 for foreigners so they now also get charged- but not capital gains tax from the day you bought the property, just from 2015.  So if you bought a property in 1980 you need to find a way to demonstrate what the house was worth in 2015 to be able to make sure the capital gains tax is charged appropriately.  Im no tax expert but this is deifinitely worth preparing for. 

Do you know if the Swiss tax authorirties demand for documentation to be translated? Obviously all documentation I have is in English or Spanish!

I am very bad on filling out tax forms and have no idea if I do it correctly.  I declared the property more than 20 years ago and am 90% sure I did not have it translated.  Forgot what I sent but it was either the lease or the purdchase invoice.  When I declare the service charge I  just send a copy of the service charge as I receive it (ie in English). If I wanted to let the flat then there is a clause in the lease that only allows me to rent it any two years in a three year period.  If I were to bother claiming that reduction of the rentable value I might have to translate that pert of it into French but I wouold hope to get away with my own unprofessional translation.  Still this is all very academic as the tax authorities have decided that I no longer live where I actually live and have lived for more than 20 years and so have failed to send me tax return. 

Beverly - you don't really need to worry too much about the paperwork, you simply submit your tax return here with the completed figures regarding your property like any other asset.  Whatever language the paperwork comes backing up what you have completed on their form should be fine as it is just confirmation of what you are already signing to be truthful.   

When you fill in your Swiss tax return, you should in principle mention the purchase price of the foreign property (or the foreign fiscal value of you have no purchase price). The important point is to mention that the proeprty is situated abroad. By this mean, it will not actually be taxed for the net wealth in Switzerland, but the amount is only used for the calculation of the tax rate (to be used on your items which are subject to tax in Switzerland, for example on your movable assets).

Concerning the income, there are two possibilities: i) either the house is not rented out and you have to announce a deemed rental value (you may indicate for example a percentage of 3 to 4% of the value of the property); ii) or the house is rented out and you announce the effective rental income. Please note that the theorectical rental income or the effective income is also used for the calculation of the tax rate, but it should not be part of the taxable base in Switzerland.

Does anyone know the capital gains tax on the profit if i sell a property in Portugal? I know its a flat rate of 28%  for the EU but not sure for a Swiss person resident in Switzerland?