The music system Sonny has in his living room is the Sony MHC-S5.
When Richard breaks into the flat he spray paints "Cheyne Stoking" on the wall. In very sick patients, this is the name of the breathing pattern that is a sign of impending death.
Toby Kebbell was cast only one day before filming started
Filming took three weeks and Toby Kebbell did all his scenes in the last week.
The end credits state the message "In memory of Martin Joseph Considine", this is Paddy Considine's father. Just before Martin died, he kept saying he wanted Paddy to work with Shane Meadows again.
Mark and Marie's two little boys Craig and Matt were played by real life brothers Craig and Matt Considine, Paddy Considine's nephews.