Matt Hancock, Health Secretary, has confirmed that from 15 February all arrivals will be required to get a test on days two and eight of their 10-day quarantine period -- this includes people isolating at home or in a hotel.
And if they test positive, they will have to quarantine for a further 10 days, he says.
This is as well as a pre-departure negative test before arriving in the UK - whether by boat, plane or train - meaning all travellers to the UK will now need three Covid tests in total to enter the country and exit quarantine.
The Health Secretary confirmed tough new measures including fines of up to £10,000 and prison sentences of up to 10 years for rule breakers.
This is all being brought into place to control new variants of the virus.
Additionally, arrivals from "red list countries" must pay £1750 for their own hotel quarantine, transport and testing, Matt Hancock announced.
"Any returning residents from these countries have to quarantine in an assigned hotel room for 10 days," he says.
These will be booked online in advance and the cost of £1750 is per person.