Travellers in Switzerland, Jamaica and Czech Republic must quarantine on return to the UK from 0400 on Saturday, the transport secretary has announced.
Grant Shapps said the move was needed to keep UK infection rates down.
People arriving in Scotland from Switzerland are already required to self-isolate.
Cuba, where there has been a drop in cases, will be added to the list of destinations people can return from without entering quarantine.
The UK considers imposing quarantine conditions when a country’s rate of infection exceeds 20 cases per 100,000 people over seven days.
Switzerland is currently over that threshold, with a seven-day rate of 21.2, while the rate in the Czech Republic currently stands at 19.4, up from 16 a week ago.