Member States were supposed to transpose these measures by 31 December 2016. The new rules are designed to help clamp down on cross-border tax avoidance, aggressive tax planning and harmful tax competition and the first exchange of information between all EU tax authorities is supposed to take place by this September. The Commission has set the 3 countries a deadline of two months to reply. In the absence of a satisfactory reply, the Commission may decide to refer the case to the Court of Justice of the EU. In the meantime, the Commission has also welcomed the transposition of the same measures by the Czech Republic, Greece, Hungary and Poland and decided today to close the respective infringement cases. In a second step, the Commission will assess whether the legislation of all Member States comply with all requirements of the new rules.