Heathrow has opened a dedicated terminal for arrivals from red list countries.
Travellers from more than 40 red list countries will be processed at Terminal 3.
The move aims to separate red list arrivals from those from amber and green list destinations.
It comes after concerns were raised about red list arrivals mixing with other passengers in busy arrival halls, with little room for social distancing.
Some 43 countries now feature on the UK government’s Covid red list, including India, Brazil, Turkey, the UAE, South Africa, Pakistan, Bangladesh and the Maldives.
Arrivals from red list destinations must self-isolate for two weeks in government-appointed hotel quarantine facilities.
The aim is to reduce the likelihood of importing new variants of Covid-19 from destinations where known new variants are in circulation, or have strong travel links with countries where they are.
Much of South America and southern Africa remains on the red list due to the so-called Brazilian and South African variants of Covid-19, with several countries near India or with travel links to the country having since been added to the red list too.