Great, thanks for this. Done some digging about with British Cycling and found this;
It is a requirement of UCI that members of British Cycling obtain a letter of authority to race abroad. To qualify for a letter of authority, you must be in possession of a current Full Racing Licence. Requests should be sent with your membership number to membership@britishcycling.org.uk
It is a requirement of UCI that all riders must be covered by adequate medical insurance when racing overseas. While the National Health Service in the UK provides for British riders competing in Britain, it may be necessary for you to take out additional travel insurance to cover you whilst you are racing abroad. For races in Europe, it is strongly advised that riders also carry a European Health Insurance Card (EHIC). Please refer to the advice above on EHIC cards.