The Vatican and Italy on Wednesday signed an agreement to share financial and tax information and the Holy See pledged full cooperation and transparency with its neighbour.
The deal, which was announced in two separate statements from the Vatican and the Italian economy ministry, came after months of negotiations and will cover information from 2009 onwards.
The Vatican has long been criticised by international financial organizations for providing a tax haven for well-connected Italians.
In particular, the Vatican bank for decades allowed many Italian citizens to hold bank accounts. That practice, which was in violation of the bank's mission to manage money for the Church, helped individuals evade taxes and launder cash, Italian law enforcement officials say.
Since the election of Pope Francis two years ago, the bank, officially known as the Institute for Works of Religion (IOR), has been undergoing change. As of July, it had blocked the accounts of 2,000 clients and ended some 3,000 "customer relationships".