The government banned travel to the UK from the United Arab Emirates (UAE), Burundi and Rwanda.
Officials said the move was to prevent the spread of the new variant originally identified in South Africa into the UK.
From 13:00 on Friday, passengers who have been in or transited through the United Arab Emirates, Burundi and Rwanda in the last ten days will no longer be granted access to the UK.
This does not include British and Irish nationals, or third-country nationals with residence rights in the UK, who will be able to enter the UK but are required to self-isolate for ten days at home, along with their household.
Passengers returning from these countries cannot be released from self-isolation through test to release.
There will also be a flight ban on direct passenger flights from the United Arab Emirates.
The decision to ban travel from these destinations follows the discovery of a new coronavirus variant first identified in South Africa, that may have spread to other countries, including the UAE, Burundi and Rwanda.
Any exemptions usually in place will not apply, including for business travel.
British nationals currently in the UAE should make use of the commercial options available if they wish to return to the UK.
Indirect commercial routes that will enable British and Irish nationals and residents to return to the UK continue to operate.
British nationals should check Foreign, Commonwealth & Development Office (FCDO) travel advice and follow local guidance.