2019-10-21 20:58:25 UTC
"The whole of the UK will leave the EU customs union. The customs union is an agreement between EU countries not to charge taxes called tariffs on things coming from other EU countries, and to charge the same tariffs as each other on things coming from outside the EU."
That, of course, would be a free trade agreement, something that is being proposed in all outcomes.
The EU customs union means the total elimination of borders and hence covers goods and services. It requires anything that could cross a border to be subject to the same laws and jurisdiction.
In the EU interpretation (which is far more comprehensive than the more typical 'partial' customs unions) is also what requires countries to adopt laws voted by an EU majority in areas were the EU has exclusive competence and it must respect changes made to areas of competence that are agreed by member states.
In fact leaving the EU and staying in the CU means being governed by laws outside your control and jurisdiction.
The EU customs union, along with the Euro, is the last step before becoming a single nation.