Businesses can currently move goods freely between EU countries. For customs purposes, this means that businesses trading with the rest of EU do not have to make any customs import or export declarations, and their trade with the EU is not subject to import duty.
In the event of a “no deal” Brexit there would be immediate changes to the procedures that apply to businesses trading with the EU. It would mean that the free circulation and movements of goods between the UK and EU would end.
HMRC is currently introducing its new Customs Declaration Service (CDS), which replaces its Customs Handling of Import and Export Freight (CHIEF) system.
From 11pm on 29 March 2019, for businesses trading with the EU, the impacts would include businesses having to apply the same customs and excise rules to goods moving between the UK and the EU as are currently applied in cases where goods move between the UK and non- EU countries.
This means customs declarations would be needed when goods enter the UK (an import declaration), or when they leave the UK (an export declaration).
For imports into the UK, a separate safety and security declaration needs to be made by the carrier of the goods (usually the haulier, airline, freight train operator or shipping line).
For exports from the UK, the export declaration includes the safety and security declaration.