The following is taken from the BBC News site and can be accessed here for the latest version.
How are the testing rules changing for people with Covid?
Across the UK (and in England from 11 January), people without symptoms who have a positive lateral flow test (LFT) no longer have to take a PCR test to confirm the result.
Instead, they must report their result online or by calling 119, and self-isolate. They will be contacted by the relevant tracing service so their contacts can be notified, as happens now after a positive PCR.
People will be able to leave self-isolation seven days after the date of their initial positive test, providing they receive two negative LFT results, 24 hours apart, on days six and seven.
The new testing guidance will remain in place while Covid case levels remain high, because the vast majority of people with positive LFT results now are extremely likely to have coronavirus.
However, anyone with Covid symptoms - a cough, a fever or a loss of taste or smell - must also take a PCR test as soon as possible, and self-isolate while they wait for the result.
They must continue to self-isolate if the PCR test is positive, even if they have previously had negative LFTs.
People who are eligible for the £500 test and trace payment in England will be asked to take a confirmatory PCR to enable them to access financial support.
Clinically vulnerable people in Wales and Northern Ireland are also still advised to take a PCR test after a positive LFT.