Sweden and Germany have been removed from the list of UK Travel Corridors, meaning anyone arriving from there after 4am on Saturday must quarantine for 14 days.
The Department for Transport pointed out that new lockdown rules mean holidays are currently not permitted.
Those in breach of the rules face penalties starting at £200 and increasing to a maximum of £6,400.
The DfT said: "Germany and Sweden have been removed from the list of UK travel corridors, having been assessed by the Joint Biosecurity Centre as posing a heightened infection risk.
"Passengers arriving into the UK from Germany and Sweden from 4am on Saturday November 7 2020 will need to self-isolate for two weeks before then following domestic rules.
"The Government's travel corridor policy remains a critical part of the Government's Covid-19 response as it mitigates the risk of importing infections from abroad; this has not changed following the introduction of new restrictions in England."