For arrivals from 8 June, there will be new rules in place for entering the UK because of coronavirus (COVID-19). The rules are for both residents and visitors. When these rules are in place, you will:
a) need to provide your journey and contact details when you travel to the UK
b) not be allowed to leave the place you’re staying for the first 14 days you’re in the UK except in very limited situations (known as ‘self-isolating’)

Link to the UK Gov directive and form

Similar rules apply for entry into Germany