This paper studies the effects of the 2017 multilateral automatic exchange of information (AEoI) on tax compliance in Switzerland. Using detailed administrative tax data and difference-in-differences designs, I document large and persistent compliance gains. The AEoI triggered around 107,000 taxpayers (about 2% of all) to enter Switzerland’s tax amnesty, disclosing CHF 37.6 billion of previously hidden wealth (over 5.5% of GDP). At the micro level, once they enter the amnesty, participants increase reported wealth by roughly 50% on average, with effects sustained in the medium run. Finally, the evidence indicates that tax evasion in Switzerland is widespread and comparatively more evenly distributed across the wealth distribution than in other countries.