People coming to the UK from France and several other countries are now being forced to quarantine for 14 days.
France, the Netherlands, Monaco, Malta, Turks and Caicos, and Aruba have been removed from the UK government's list of countries exempt from quarantine rules.
When did the new restrictions kick in?
The rules for the new additions to the list, including France, came into effect at 04:00 BST on Saturday 15 August.
Will I be covered by travel insurance?
If you arranged your own earlier flight or ferry ticket home before the measures took effect, it is extremely unlikely you will be able to claim the cost back from an insurer or anyone else, our personal finance reporter Kevin Peachey says.
In the unlikely event that your flight back was cancelled and the airline placed you on an earlier flight, then you should not be out of pocket, he adds.
What do I have to do when I get back?
Anyone arriving to the UK has to complete a passenger locator form giving their passport information and details about where and when they have travelled.
All travellers - including UK nationals - coming from countries that are not exempt from quarantine must provide the address where they will be staying.
What does quarantine mean, and what if I break the rules?
When you arrive in the UK you will need to self-isolate for 14 days.
Self-isolating means remaining at home or the place you are staying - and not leaving it. So you cannot go shopping or meet friends, and any exercise you do must be in your home or private garden, if you have one.
People can be fined £100 for failing to fill in a form with these details.
One in five eligible passengers will be called or texted to check they are following the rules.
People who do not self-isolate can be fined up to £1,000 in England, Wales and Northern Ireland and £480 in Scotland. There are fines up to £5,000 for persistent offenders.
Can I still go on my holiday?
If the new rules will affect your ability to work when you return to the UK, it could mean having to cancel your trip.
In cases where only quarantine rules are changed, you are unlikely to be able to get your money back from tour operators, airlines or hotels.
However, if the Foreign Office also advises against travel to a country - as is now the case for France - then a refund for the whole holiday or the opportunity to rearrange it should be granted.
Some people are exempt from the quarantine rules, including Eurotunnel train drivers, road haulage workers and military personnel.