For development of mobile banking, co-operation between the banks and the mobile service providers’ is important. World over the race for mobile companies to become banks and banks to become mobile service providers have failed. Mobile transaction platforms initially designed by banks or mobile service providers based on this race have resulted in silos, which provide only limited transaction ability and almost nil interoperability.
And by the way, that is also an issue for European banks that do business in the UK. They keep the EU passport, of course, but might lose access to the UK market. So, once the UK has left, banks that operate from there might have to seek another route into the European market.