Looking at the new digital challenges of the 21st century, Tax Summit brings together experts from tax administrations from all over the world in Lisbon to discuss and reflect on the challenges of taxing the digital economy. This event results from the partnership between CIAT - Inter-American Center of Tax Administrations, IOTA - Intra-European Organization of Tax Administrations and AT - Tax and Customs Authority. In focus will be the topics related to new technologies and their impact on the world of taxes.