Just what is the customs union?

A customs union is a form of trade agreement between two or more countries

The EU’s comprises all 28 members plus Monaco. The EU also has limited agreements with Andorra, San Marino and Turkey

Countries in the union do not impose tariffs on each other’s goods as they cross borders

Member states also apply the same tariffs on imports from countries outside the customs union. Once goods have entered the customs union they move freely between member states

A customs union differs from a free trade area, which allows members to trade freely with each other while setting their own tariffs on goods from the rest of the world

As a member of the EU customs union, the UK cannot negotiate its own trade deals elsewhere, and has no free trade agreements of its own. The deals it does enjoy, such as with Canada and Japan, are through the EU

Many Brexiteers want Britain to leave the customs union as it would prevent us striking new bilateral trade deals with places such as the US, China and India