Non-residents income tax liability
Non-residents are liable for this tax on any income arising in Spain, such as a money deposit with a Spanish bank, a property in Spain, or income derived of any business in Spain.
Property owners are taxed on their property income. The tax base is the property cadastral value (valor catastral), which can be found on any I.B.I receipt. Tax base rate is 25% of a 2% of the cadastral value.
Should you fail to pay this tax, you will be charged and penalized by the Spanish Tax Agency if you try to sell your property.