In order to enter the UK, you will need to book a UK arrivals test which will be sent to your UK address and needs to be performed on either day 2 (or before), or day 2 and 8 depending on your vaccination status. Before you arrive to the UK, you will need to have proof that you have booked your arrivals test by providing a passenger locator booking reference number into the UK government passenger locator form which is completed within 48 hours of arrival.