I had to register for Income Tax specifically for EU Deposit Interest recently. The registration process is cumbersome and far from intuitive and there were a number of roadblocks along the way to registration. At each of these I entered details of the issue on My Enquiries, then waited 5-7 days for a response, and when I got it moved another few cm forward, met the next obstacle, entered the details on "My Enquiries", waited 5-7 days....... rinse and repeat basically. The "business description" I was told to use was "Eu deposit interest" and I was told to leave all other fields blank, however I was unable to enter anything because of leftovers from a previous registration, so that required another "My Enquiries" manual intervention.