His films include The Forgotten Battle (2020), Avatar: The Way of Water, The School for Good and Evil (both 2022), and Black Dog (2023).
[2] Flatters was in an alternating role, as Edgar, in the original Tricycle Theatre cast of the 2013 play Bracken Moor.
Flatters made his television debut in 2015 as Matt Furnish in the CBBC sitcom So Awkward, a role he played for the first two series.
[11] In May 2024, Flatters joined the cast of PBS Masterpiece new adaptation of The Forsyte Saga as Philip Bosinney.
[17][18][19][20] Flatters has advocated for lowering the UK voting age to 16, and became a member of the Almeida Theatre's Young Leaders programme.