Joe Claflin was offered the role of George Foxim.
During the press conference scene, a lot of the journalists can be seen wearing badges with 'Vote for Montag' or the Montag logo 'M' on them.
The Montag 'M' can be seen on a flag hanging on a building during the street chase scene.
John Mangan only accepted the role of Hilary Montag a few days before shooting. The actor who originally had been cast broke his foot during a storm and had to drop out.
The assassin character was inspired by Arby from Channel 4's Utopia played by Neil Maskell. Neil Maskell played Sean McGann in Evil Never Dies which was written and starred John Mangan who plays Montag in Above the Fold.