Aside from Capital Gains, Wealth and Inheritance Taxes, non residents must pay tax on any income that arises in Spain. Income tax for non-residents is charged at a fixed rate of 19% if you are a resident in an EU or EEA country, and for non-residents from the rest of the world the rate is 24%.
Non-Residents Property Tax on No Income
If you own a property in Spain and earn rental income from it, then this has to be declared. What many non-resident owners of property in Spain are not aware of, is that they are also required to pay tax, regardless of whether the property is let out or not!
This tax is often referred to as an imputed income tax. Spanish tax legislation for some reason assumes that a non-resident owner derives some sort of benefit from owning property, whether true or not, and provides a system to tax it.