According to CNN Travel, the UK reopened its borders to non-essential travel just last May 17, 2021. Those who want to go to England, Scotland, and Wales will now be able to do so as long as they can provide proof that they've been vaccinated or that they tested negative on Covid-19. For the latter, the PCR test should have been taken recently, at least 72 hours prior to arrival. Currently, England is in its third phase of easing its restrictions, allowing various establishments, from museums to restaurants, to reopen but with limited capacity. Scotland and Wales, on the other hand, remain stricter with their restrictions.
Prior to the May 17 reopening, the UK adopted a traffic-light system that classifies which countries they can let enter the country with no restrictions and which ones will remain banned in the meantime. Those from 'green countries' are allowed entry to the UK with very few travel restrictions. Those from 'amber countries' will have to quarantine for around 10 days upon arrival and take PCR tests on the second and eighth days of the quarantine period. If any of those tests remain negative, they will be allowed to travel freely within the country. And those from 'red countries' will have to strictly go into the 10-day quarantine without any PCR tests.
These new developments come after the UK decided to ease its travel restrictions following a third national lockdown that started back in January. That lockdown was a response to a new variant of Covid-19 that was discovered in the UK which was more infectious than the original version of the disease. Because of the new variant and an uptick of cases in the country, the UK has had 4,400,000 cases and 127,900 as of May 24, 2021. Because of this, various countries around the world still ban travelers from the UK from entering their borders. And this comes after another CNN Travel report stating that UK residents are now allowed to travel internationally again.
Unfortunately, many countries that ban travelers from the UK are those from the EU. As well as the US according to TravelPulse. For now, because of the new variant, the UK remains on the 'red list' of various Schengen countries. However, this might soon change. By June 2021, the EU will fully implement its Digital Green Certificates, a vaccine passport system that will allow travelers free movement within the region. These certificates will be given to travelers both from within the EU and from outside of the continent. The Independent reports that the UK may join this system despite exiting the EU back in 2016.