The Spanish government has made - and continues to make - numerous policy changes affecting public revenues and expenditures in response to the global financial crisis. Among them is the extraordinary measure of tax amnesty introduced by Royal Decree 12/2012, of March 30, which seeks to increase public income by establishing a special rule for public taxation of undeclared assets. The tax amnesty is an institution marked by the sense of urgency and the need for resources resulting from the economic crisis. However, such regulation raises certain questions and issues: What is tax amnesty? Does it affect the principle of tax equity? What are the punitive consequences?