What is the Union Customs Code?

The Union Customs Code (UCC) is the rulebook for managing the external borders of the EU’s customs union. It is relevant in a Brexit context because these are the rules and procedures that will be put in place on the EU side of UK-EU border points after the end of the transition period. Notably, as a result of the Northern Ireland protocol, the UCC will also be applied on goods trade between Great Britain and Northern Ireland.