Batbrit. I cannot find the web page you show, but as said in another answer to a post of yours, the 720 only applies to those who are tax resident in Spain.
And yes the fines for not complying are very high (starting at 10,000 euros and up to 150% of the assets not disclosed) nevertheless, it seems that less than 5% of those who were thought to be obliged to make a return, failed to do so.
See http://imontlegalservices.com/index.php/en/noticias-2/61-form-720-new-tax-declaration-for-residents-in-spain
This message was last edited by johnzx on 30/04/2014.