Government minister Michael Gove has said there will be “practical and procedural changes” at the end of the Brexit transition period on 31 December.
Travellers heading to the EU have been urged to check things such as mobile phone roaming charges and to ensure they take out comprehensive travel insurance.
Brits heading to the EU will also need to make sure they have at least six months left on their passports.
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 also reminded 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 added.
"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."
Other changes will include the need for GB stickers on your car when driving in the EU after the transition period ends.
Abta has also warned drivers to ensure they carry a physical Green Card for their UK car insurance to be valid in the EU.
The Brexit deal was agreed on 24 December, with representatives of EU governments set to sign the deal between 27 and 31 December to ensure it is applied provisionally.
On 30 December, UK parliament will be recalled to vote on the deal before the Brexit transition period then ends on 31 December.
Abta has also produced a snapshot guide to what travellers should check before heading to Europe from 1 January 2021.
