Holiday hotspots such as Malta, Ibiza and some Caribbean islands are cleared for Brits to visit without quarantining on their return.
However, some countries - such as Australia, New Zealand and Iceland - are not currently accepting visitors from the UK, despite being on the green list.
The most popular European destinations with UK holidaymakers – such as Spain, Italy, France and Greece – are on the amber list.
What are the rules for people returning from each category?
Green: No need to self-isolate. Take a pre-departure test and a PCR test on day two of your arrival in the UK.
Amber: Self-isolate for 10 days, unless you are double-vaccinated, under 18, or receive a negative test result at least five days after arrival. Take a pre-departure test, and PCR tests on day two and day eight of your arrival in the UK.
Red: Spend 10 days in a quarantine hotel. Take a pre-departure test, and PCR tests on day two and day eight of your arrival in the UK. Travellers are only allowed into the UK if they live here.
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Here is a look at the green and red categories.
Arrivals to the UK from these countries do not need to self-isolate, but will need to present negative Covid-19 tests.
British Virgin Islands
Travellers from these countries do not need to self-isolate but are warned that these countries are at risk of moving to the amber list, where they may need to self-isolate.
British Antarctic Territory
British Indian Ocean Territory
Madeira (Mainland Portugal and the Azores are on the amber list)
Turks and Caicos Islands
Arrivals to the UK from these countries need to self-isolate for 10 days, unless they have been double-vaccinated in the UK, under 18, or receive a negative test result on day 5.
From 4am on Sunday August 8, India, Bahrain, Qatar and the United Arab Emirates will be moved from the red to amber list. France will also fully move back to the amber list, after the government said that even those who were fully vaccinated needed to quarantine for 10 days after arriving back to the UK, unlike other countries on the amber list.
The countries above join more than 130 other countries on the amber list, including popular holiday destinations such as Spain, Portugal and Italy. The full list of amber list countries can be found on the UK government website.
UK residents arriving from these countries must quarantine for 10 days in a hotel. Non-UK residents from these countries are not allowed here.
Democratic Republic of the Congo
Trinidad & Tobago
United Arab Emirates (UAE)
Stay up to date with the changing travel situation in the UK and abroad with news, information and advice at itv.com/holidaynews