What is the customs union?

A customs union is a group of countries that trade without tariffs between themselves and charge the same tariffs on goods from outside. The EU customs union means members cannot sign their own trade deals. The UK left it at the end of 2020, so it can now set its own tariffs.

Inside the EU customs union, goods move between members without tariffs or customs checks. All members apply the same tariffs on imports from outside, and the EU negotiates trade deals for them all. Turkey has a separate customs union with the EU for most goods. After leaving, the UK started its own trade policy. It signed deals with countries such as Australia and New Zealand, and joined the CPTPP. But UK and EU firms now fill in customs declarations and may face checks. The UK and EU trade deal avoids tariffs on most goods if they meet 'rules of origin'. Northern Ireland has special arrangements to keep the Irish border open. Rules of origin require enough of a product to be made in the UK or EU to qualify.