Disclaimer : I am not a lawyer or financial profesional. Do your own due diligence and don't take my word on anything. These are my own tips and thoughts. If you have foreign assets outside of Spain in excess of €50,000 you may have to file the Modelo 720 (Form 720) each year prior to March 31st.  There are no taxes associated with Modelo 720, it's only an informative filing.  There are fees and fines