A few gulls about in Dartford, Kent, today including this individual. I'm happy that it's a Yellow-legged Gull but would appreciate a few more 'nods' (or otherwise).
Tertials look good and the white edges don't appear to meet the greater coverts. Head shape good too and bill is long, broad and rectangular. Wing coverts darker than on a typical Herring and the pattern of the scapulars look good too with thin dark shafts and narrow 'double headed anchors'.