From next month, fully vaccinated people travelling to the UK will no longer have to take any Covid tests - either before departure or after arrival.
For the first time since the pandemic began, Wales has also stopped advising against non-essential foreign travel.
What changes are coming into force?
From 04:00 GMT on 11 February, fully vaccinated travellers (two doses) and under-18s will no longer need to take a lateral flow test two days after they arrive in England, Scotland, Wales or Northern Ireland.
Travellers who aren't fully vaccinated will no longer have to self-isolate on arrival, or take a test on day eight.
However, they will still have to show proof of a negative Covid test taken two days before they travel, and they must still take a post-arrival PCR test. They won't need to self-isolate unless the day two test is positive.
To qualify as vaccinated, non-UK travellers must have received their jabs in a country or territory with "approved proof of vaccination". This now covers most countries in the world, with more - including China - due to join on 11 February.
All passengers will still need to fill in a passenger locator form.
What are the current rules for vaccinated travellers to the UK?
Fully vaccinated passengers (who have had two doses) and under-18s no longer need a pre-departure test two days before travelling to the UK.
However, within 48 hours of arrival, everyone aged five and over (11 and over in Scotland) must take a lateral flow test (LFT), or a more expensive PCR test.
The test must be bought from a private test provider - free NHS tests cannot be used.
If they take an LFT and it is positive, they must self-isolate and take an NHS PCR test to confirm the result.
Vaccinated travellers also have to fill in and submit an online passenger locator form no more than 48 hours before arriving, even if they are just passing through the UK.
What are the travel rules for everyone else?
All unvaccinated travellers to the UK must complete a passenger locator form, and take an LFT or PCR in the 48 hours before departure.
The test can be taken either in the country where you start your journey, or in another country en route to the UK.
If you test positive, you must follow the rules in the country you're in, and not travel onwards to the UK.
If you've not been fully vaccinated you must quarantine for 10 days after arrival in the UK.
You must also take two PCR tests - on days two and eight of your quarantine.
These must be booked before travelling to the UK and bought privately from a government-approved list of providers.
Travellers to England also have the option of ending quarantine under the Test To Release scheme - this involves taking a private PCR test after five days of isolation. A negative test will allow them to leave quarantine, although they must still take another PCR test on day eight.
These rules do not apply to travellers from Ireland, the Channel Islands or the Isle of Man, unless they have been in another country in the 10 days before their departure for the UK.
How do I prove vaccinations and test results at the UK border?
Test results can be in the form of a printed document, or an email or text on your phone. They must be in English, French or Spanish.
European Union residents can use the EU Digital Covid Certificate to show their vaccination status or test results.
From 3 February, 12 to 15-year-olds in England will also be able to prove their vaccination status via the digital NHS pass.
What about other countries' rules?
You need to check the UK Foreign Office website for entry requirements of any other countries you visit. These can change quickly.
Covid passes issued in the UK can be used throughout the EU to show proof of vaccination - either digitally, or as a printed download (as long as it is dated later than 1 November 2021).