Chancellor of the Duchy of Lancaster Michael Gove has told firms that import checks at the UK border will come into force and frictionless trade with the EU will cease at the end of 2020.
Speaking at a Border Delivery Group conference, Gove said: "The UK will be outside the single market and outside the customs union, so we will have to be ready for the customs procedures and regulatory checks that will inevitably follow.”
Gove added that there would be some minimal trade related administration between Great Britain and Northern Ireland, but major Irish Sea ferry operator Stena Line is thought to be preparing for full-scale trade checks.
Government officials have said that businesses will be given sufficient notice to prepare for changes in time for January 1, 2021, when they enter force.
Goods traded with the EU will then be subject to checks relating to customs, regulatory standards and food safety, and all trading firms will be required to submit customs declarations.
A new customs infrastructure will need to be implemented before the end of 2020, including new facilities, systems and staff, which includes vets to regulate products of animal origin.
Vets will be needed to provide export certificates which will be required under the new regulatory framework to accompany any products which come from animals.
Tariffs will also be levied on goods going over the border if there is no UK-EU trade deal in place by the end of the year.
Andrew Opie, director of food and sustainability at the British Retail Consortium, warned of a race against time to get the necessary customs network in place.
He said: “Government will need to move fast if it intends to provide the necessary infrastructure to carry out full border controls on imported goods from January 2021.
"Without the necessary infrastructure up and running from day one, consumers in the UK will see significant disruption, particularly in the availability of fresh fruit and vegetables.”