Fully vaccinated passengers returning to the UK from amber list countries no longer need to isolate.

France has been removed from the amber-plus list, and is now covered by the normal amber-country rules. This means under-18s and fully vaccinated passengers returning to the UK no longer need to self-isolate for 10 days.

The green list - which has no quarantine for returning passengers - has also been expanded. Countries listed now include:
Austria
Bulgaria
Croatia (green watchlist - could be moved to amber)
Germany
Malta
Norway
Romania
Slovakia
Slovenia

Four countries have moved from the red to the amber list: India, Bahrain, Qatar and UAE.
But Reunion and Mayotte, both French islands in the Indian Ocean, are now on the red list, along with Mexico and Georgia.
Which tests do I need?
Going on holiday abroad means taking Covid tests.
You may need one before setting off - each country has its own rules for arriving holidaymakers.
Then, in the three days before returning to the UK, you will need to take a PCR or lateral flow/antigen test. You will need to show a negative result before boarding and cannot use the free NHS tests.
Lateral flow/antigen tests can be bought in the UK to take with you, or you can buy these or PCR tests when you are away.
It is your responsibility to make sure they are of the right quality.

The government now advises passengers returning from Spain to use a PCR test instead of a lateral flow test.

For green- and amber-list countries a further PCR test is needed after arrival in the UK, which must be booked before you leave.
Most private providers charge above £60 for PCR tests and £30 for lateral flow devices. Some travel companies offer discounts.
Javid urges review of excessive Covid test costs

Green list banner
What are the rules for green-list countries?
Nobody has to self-isolate after visiting countries on the green list.
Returning from a green-list destination, you must:
Take a Covid-19 test before departure and have proof of a negative result
Book a test for day two after your return (children aged four and under do not need to take these)
Complete a passenger locator form
You only need to self-isolate on return from these countries if your day two test is positive, you develop symptoms or NHS Test & Trace says you've travelled with someone who tested positive.

Amber list 
What are the rules for returning from an amber-list country?
The vast majority of countries are on the amber list.
Adults fully vaccinated in the UK, the US and most European countries don't have to self-isolate upon arrival in the UK.
A Covid test is needed three days before returning from an amber country, and a PCR test two days after arriving.
Those arriving from Spain are being asked to use a PCR test for the first of those two tests.
Under-18s do not have to self-isolate. In England, Wales and Northern Ireland, children aged 10 and under don't have to test before travel, but do need to take one two days after arrival. Those aged four and under don't need any tests.
In Scotland, children over 12 have to take tests before returning home, and on day two.
How can I prove I'm fully vaccinated?

Red list 
What are the rules for red-list countries?
Red-list countries are those the UK government says present the highest Covid risk, and should not be visited "except in the most extreme of circumstances".
Dozens of countries are on the red list, including Pakistan, Turkey, Brazil and South Africa. If you have been in one in the last 10 days, you can only enter the UK if you are a UK or Irish national, or UK resident.
Returning from a red-list country - regardless of your vaccination status - you must:
Take a Covid-19 test before departure and have proof of a negative result
Complete a passenger locator form
Self-isolate for 10 days in a government-approved quarantine hotel, booked and paid for in advance

From 8 August, rates are:
10 days (11 nights) for one adult - £2,285
Additional adult (12 and over) - £1,430
Children aged five to 11 - £325