Holidaymakers returning from three countries will now have to self isolate for 14 days. Quarantine rules have been introduced in the UK for anyone arriving from Croatia, Austria, and Trinidad and Tobago.
In Scotland the measures also apply to arrivals from Switzerland. Many people on holiday in these countries, which have all seen a spike in coronavirus cases, tried to change their flights at the last minute to beat the deadline.
Reeta Chakrabarti presents BBC News reporting by Frankie McCamley at Gatwick Airport.