The Constitutional Court has nullified the tax amnesty, considering that the decree which approved it is unconstitutional. The Court, sitting in plenary session, has thus admitted the appeal, which held that the amnesty approved by the government in 2012 violated the principle of equality. Nevertheless, it has been nullified because, as the Court states, the rule prohibited the use of the decree-law when the measures approved have a “relevant or substantial” effect on the obligations established in the Constitution, as is the case of the "constitutional obligation of 'all' to contribute to sustaining public spending."

The Court’s judgement establishes that "The legal-fiscal situations produced under the protection of the amnesty must be declared unrevisable as a consequence of the nullification of Additional Provision One of Royal Decree-Law 12/2012, due to the constitutional principle of legal safety (Article 9.3 of the Spanish Constitution)." Apart from the abovementioned, we understand that generally taxpayers who took the tax amnesty will not be affected by the declaration of nullification insofar as it includes undeclared income earned in Fiscal Years 2008, 2009, and 2010. Today, these fiscal years have passed the statute of limitations tax-wise. Therefore, the Tax Administration may not initiate actions relating to those years and demand payment of the taxes due for those periods.