Despite serious consequences for lying about their recent travel history, including jail sentences, some passengers will probably attempt to circumvent the rules to avoid having to quarantine in a UK hotel, aviation experts said.
People arriving in England from the red list of 33 countries now have to spend 10 days in quarantine in hotels.
Experts said enforcing the new rules would be a challenge and the biggest issue was going to be the element of honesty.
Saj Ahmed, chief analyst at StrategicAero Research, an aviation consultancy, said many will transit through a third country and lie about their original country of departure.
"There is always going to be that traveller that will be dishonest," he said.
“It will be hard to police. The smarter traveller will try to circumvent the rules and get away with isolating at home.
“Though not advisable, I think we will see a lot of people choosing to fly to Europe first, then to the UK.
“Due to the exorbitant cost of the hotel quarantine, they might only declare the second leg of their journey.”
Mr Ahmed was among several experts who said mandatory quarantine measures were not the answer in terms of a global recovery for the travel industry.
Instead, focus needs to be on regular testing and it should not be “forgotten or side-tracked in place of quarantine”.
Last week, the tourism industry accused the UK government of trying to scare people into not going abroad after ministers announced a potential 10-year prison sentence for travellers who lie about where they have been.
The red-list countries affected by the ban include the UAE, Brazil, Portugal and South Africa.
The new regulations were brought in to stop Covid variants entering the country, but the decision was met with a lot of frustration.
John Strickland, director of aviation consultancy JLS Consulting, said enforcing the rules will be very challenging for airlines and for border control in the UK.
“[There has been] little or no consultation with the airlines or industry bodies, so the practicalities are not thought through,” he said.
“You can have a red list flight ban but certain people can travel indirectly and I don’t see an easier way that can be enforced, other than to have airlines sift out passengers before they travel.
“It has the potential to have leaks.”
Mr Strickland said while there may be an onus on airlines to check a passenger's travel history, the process, in reality, is not simple.
He said Australia “implemented systems far more rigorously”, where officials went on board flights to check the details of every passenger.
“This [UK ban] does really look like it has been put together without any expert input from industry players, and very much at the last minute,” he said.
“In fact, the rules on quarantine hotels issued last on Friday were extensive.
“They go to pages of paragraphs and sub-paragraphs. How you’re looking to airlines, airport authorities, or indeed passengers themselves, to digest that and follow it to the letter with limited notice, beggars belief.”
Travel journalist Simon Calder said the UK had done things rather differently from much of the rest of the world.
“The hotel quarantine policy has been brought in 11 months behind many other countries, at a time when Britain's infection rates are still extremely high,” he said.
“It poses yet more problems for airlines, cuts off the UK from the main international hub of Dubai and will cause yet more damage to inbound tourism to Britain.
“My prediction is that it will be quietly forgotten by the end of March and normal links will resume.”