People entering the UK from most other countries must self-isolate for two weeks.
Many of the "travel corridors" set up to allow tourists to avoid restrictions have been suspended.
From Sunday, people arriving from Italy will also have to quarantine, but restrictions on Crete will be lifted.
Where can I go without quarantining?
In early summer, travellers could visit popular holiday destinations such as Spain and France without having to quarantine.
There are now only a handful of places that travellers from England can visit without encountering restrictions - either when they arrive at their destination, or return.
These include:
- Greece - quarantine restrictions for Crete will be lifted on Sunday, but will remain in place for Mykonos
- Foreign tourists can fly into Cuba at certain entry points
- Gibraltar
- Travellers who haven't recently visited parts of the UK deemed ''high risk'' can visit Germany without quarantining
- Madeira and the Azores - if travellers cannot show proof of a recent negative test, they will be tested on arrival and have to quarantine until the result comes back (about 12 hours)
- Sweden
There are separate exemption lists for Scotland, Wales, and Northern Ireland.
Travellers from the common travel area (CTA) - the Republic of Ireland, the Channel Islands, or the Isle of Man - are exempt from UK quarantine.
However, some parts of the CTA, including Ireland and the Isle of Man, impose restrictions on travellers entering from England.