Brexit: 'Bumpy' period expected as UK adjusts to new EU rules
There will be "bumpy moments" for UK businesses and travellers as they get to grips with new EU rules, says government minister Michael Gove.
He said there would be "practical and procedural changes" when the Brexit transition period ends on 31 December.
Mr Gove also urged people going to the EU to make extra checks, including mobile phone roaming charges.
EU ambassadors have approved the post-Brexit trade deal, paving the way for it to take effect on 1 January.
Under EU rules it can take effect provisionally, though the European Parliament will vote on it in January.
In the UK, MPs will vote on the deal on Wednesday.
Meanwhile, UK International Trade Secretary Liz Truss said she expects to sign a continuity trade agreement with Turkey this week - a move that was not possible until the deal with the EU was struck.
Mr Gove told BBC Breakfast: "I'm sure there will be bumpy moments but we are there in order to try to do everything we can to smooth the path."
He warned businesses that time was "very short" to make the final preparations before the transition period ends.
"The nature of our new relationship with the EU - outside the Single Market and Customs Union - means that there are practical and procedural changes that businesses and citizens need to get ready for," he said.
"We know that there will be some disruption as we adjust to new ways of doing business with the EU, so it is vital that we all take the necessary action now."
Businesses have been urged to make sure they understand the new rules on importing and exporting goods, including the different rules that apply to trade with Northern Ireland, and to consider how they will make customs declarations on EU trade.
Mr Gove also encouraged travellers to EU destinations from 1 January to take out comprehensive travel insurance, check their mobile phone provider's roaming charges and make sure they have at least six months left on their passports.