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 for incorrect or late filing. The €50K asset limit applies to three separate categories: Cash / Bank accounts, real-estate, and brokerage accounts. The filing is due each year prior to March 31st. In some was this is the Spanish version of the US FBAR.