Plaited Door Snail Cochlodina laminata
I'm no snail expert but this immediately struck me as different to the commoner Two-toothed Door Snail Clausilia bidentata which I've recorded a few times. The main difference was the texture of the shell - there was a suggestion of vertical striae but these were much weaker (so the shell much smoother) than I'm used to seeing on bidentata.
Plaited Door Snail Cochlodina laminata showing tail, Wendling Beck Environment Project (Norfolk, UK), 7th May 2023