The free trade agreement with the EU can no longer be used. Switzerland's trade agreement with the United Kingdom and Northern Ireland will take its place.
The UK is therefore also no longer a member of the countries that do not require security data. For exports and transit to Great Britain, security data must be recorded.
For transit to Northern Ireland, the new customs offices (beginning with XI...) must be used.The Eurostat currency code for the British pound (GBP) must now be 5 (=Other) instead of 3 (=Other EU currencies).