Brexit will result in a substantial structural change to the EU’s financial architecture over the coming years. It could be particularly significant for derivatives clearing, investment banking activities and securities and derivatives trading as the reliance on service provision by UK financial firms is more pronounced in these areas and the provision of such services is currently linked to the EU passporting regime. At the same time, the precise overall impact of Brexit on the EU’s future financial architecture in general ？ and on these specific areas in particular ？ is difficult to predict at this stage, and may change over time. This special feature makes a first attempt at analysing some of the factors that may affect the EU’s financial architecture post-Brexit. It focuses on areas which currently show strong reliance on the UK and are of particular relevance for the ECB under its various mandates.