I have added British-made films first released in 2017 (see below for details) with a Rotten Tomatoes score above 60%, i.e. a 'fresh' rating.
This list includes feature-length British films that have their premieres in 2017 and were at least partly made by Great Britain or the United Kingdom. It does not feature short films, medium-length films, made-for-TV films, adult films, filmed theater, VR films and interactive films. It does not include films screened in previous years that had official release dates in 2017.
Here is the 2018 list:
https://www.listchallenges.com/list-of-british-films-of-2018
2019:
https://www.listchallenges.com/list-of-british-films-of-2019
2020:
https://www.listchallenges.com/british-films-of-2020