Due to Brexit, large international banking groups have been restructuring their businesses with European clients since regulated institutions based in the UK will no longer be able to use the European Passport. While many firms have established new hubs in the EU 27, there are others which are considering providing services on a cross-border basis to European clients directly from the USA, Switzerland and other third countries, including the UK. This article addresses the question as to whether third-country firms are allowed to provide investment services in Germany without a license and whether German organisational and business conduct rules would apply.