LONDON — No more seamless access to medical care. A spike in cellphone bills. And months of preparation if you are bringing the dog.
For Britons who have lapsed into complacency about crossing the English Channel in the four years since they voted for Brexit, the situation will soon get a lot more complicated. Up until now, the biggest problem they faced was driving on the wrong side of the road when reaching France.
With Brexit grinding into its final phase, a government publicity drive is warning that Britons will lose health care rights in European Union countries and could pay roaming fees when using cellphones there.
Perhaps as alarming for a nation of dog lovers, roaming freely will be harder for British pets. Owners must plan four months in advance to secure the paperwork to take them.
Britain formally left the European Union in January but is honoring most of the bloc’s rules until a transition period ends in December. After that Britain will be outside the bloc’s economic structures and can proceed with plans to tighten immigration controls and strike trade agreements around the globe.
But for travelers, and many businesses, the end of the transition period means more of one thing often regarded as a specialty of the European Union: bureaucracy.
“For ordinary travelers it means getting ready for paying more and for more inconvenience,” said Anand Menon, a professor of European politics and foreign affairs at King’s College London. “For business, the government is telling them to get ready for an enormous amount more paperwork.”
Even assuming Prime Minister Boris Johnson strikes an agreement with the bloc that guarantees no tariffs or quotas on trade, more controls on imports and exports are inevitable.
That is the outcome of leaving the bloc’s single market and customs union — something Mr. Johnson has promised to do — a system that allows thousands of trucks to roll off ferries between Dover and Calais each day, mostly without stopping.
According to British government estimates, the change of rules will require an additional 400 million customs declarations each year, adding a significant cost to businesses.
The government has said it will spend more than 700 million British pounds — about $880 million — on infrastructure plans and will build around a dozen facilities near ports to process imports.
If the technology works as planned, while trucks are crossing the Channel, their drivers will be instructed by text message whether they are required to stop at a special site either at a port or nearby. Others will be allowed to complete formalities at their destinations.
“We are committed to working closely with businesses and the border industry to help deliver not just a fully operational border at the end of the transition period, but also the world’s most effective and secure border,” said Michael Gove, a senior Cabinet member with the title of Chancellor of the Duchy of Lancaster.
But he acknowledged that a new customs system will not be fully functioning until next July, so Britain will effectively wave many European trucks through ports for several months.
The customs change poses big economic risks. One business lobbying organization, the Institute of Directors, surveyed 978 members and found less than a quarter were fully prepared. One in seven said they were distracted by the coronavirus crisis and almost one-third wanted the details of the new system to be clear before adjusting.
“With so much going on, many directors feel that preparing for Brexit proper is like trying to hit a moving target. Jumping immediately into whatever comes next would be a nightmare for many businesses,” said Jonathan Geldart, director general of the Institute of Directors.
Part of the problem is that Britain has been here before, having missed successive deadlines last year for its departure from the European Union. In 2019, some businesses prepared for a rupture only to find it unnecessary.
So this time, the government needs to ensure that companies know change is coming, even before it is clear how much the disruption can be minimized.
Travelers too need to know that the rights many have taken for granted, like working or retiring in continental Europe, are at an end. So the government campaign, with a slogan “The U.K.’s new start: let’s get going” is warning Britons, for example, that they will no longer be able to use a European pet passport system and will need different paperwork.
Mr. Johnson, who was elected with the help of many voters in northern, working-class districts, is unlikely to fret about upsetting affluent, pro-European Britons who commute with their pets to vacation homes in rural France.
On Monday the government also announced details of a new immigration system to be introduced next year, once Britain ends the free movement of European Union workers.
The home secretary, Priti Patel, said the system would “attract the best and brightest from around the world,” but many low-paid workers will be excluded, which has alarmed several types of employers that rely on them, including nursing-care institutions.
But the government hopes that such employers will have to increase wages to attract Britons to perform those jobs. That upward pressure on earnings could prove popular in economically disadvantaged parts of the country, which Mr. Johnson has promised to help by “leveling up” prosperity.
So far, the prime minister has paid no political penalty for taking a hard line over Brexit, and the leader of the opposition Labour Party, Keir Starmer, has not called for an extension of the transition period.
If the disruption to trade and travel is severe, however, criticism is certain to grow.
And the government has struggled to provide much evidence of the opportunities it promised would flow from leaving the European Union.
“The change of tone was clear last year in the Conservative election campaign slogan,” said Mr. Menon. “Let’s ‘get Brexit done’ implied that this is something to get out of the way.”