From 15 December 2021, all remaining countries were removed from the UK travel red list. The red list policy and additional testing measures in response to Omicron remain in place. As such, passengers arriving from Angola, Botswana, Eswatini, Lesotho, Malawi, Mozambique, Namibia, Nigeria, South Africa, Zambia and Zimbabwe will not have to stay in a managed quarantine hotel on arrival from this date. Pre-departure tests and PCR testing measures on or before day 2 remain in place, with a review of all travel measures in the new year. Airlines must continue to check all passengers for pre-departure tests alongside their completed Passenger Locator Form, and passengers will not be allowed to board a flight without providing evidence of a negative test result.

See: https://www.gov.uk/government/news/11-countries-removed-from-the-uks-red-list?utm_medium=email&utm_campaign=govuk-notifications&utm_source=8bb63897-ce51-4418-8ec9-b020ea65472d&utm_content=daily