Taxes in Spain
You are not fully taxable if you do not reside permanently in Spain. As owner of a house in Spain you will still have to pay some taxes. You need an NIE number (número de identidad de extranjer), which is a fiscal number, to be able to file your taxes. You will also need this number in doing business with your Spanish bank. You can apply for an NIE number with the local police station. The gestor can also apply for an NIE number on your behalf.
There are three sorts of tax in Spain: national tax, regional tax and municipal tax. The tax rate will vary in each municipality, so gather as much information as you can from various municipalities. Taxes you will most certainly have to pay as owner of house in Spain are transfer taxes, rates and income tax. If you sell your house in Spain you will have to pay capital gains tax.
For more information please go to the website of the Spanish Tax Office.