If by the 29th of March 2019 the UK leaves without an EU deal, there will be rapid changes for every business who trades with the EU.
Customs, excise and VAT procedures to goods traded with the EU would have to be applied.
This is similar to how businesses from outside the EU would have to follow procedures if trading within the EU.
In order to anticipate that, HMRC have published a Partnership Pack to help businesses prepare for the 29th March 2019 if a no deal Brexit takes place. What’s included within the pack is an advanced guide to customs processes that are likely to take place in the potential no deal scenario.
The link for the pack can be found below: