One alias used by the conspirators is 'Markus Wolf' which refers to the famous head of the East German foreign intelligence service by the same name. One of his biggest achievements was to place a top spy, Günter Guillaume, as an aide to the former Chancellor of West Germany, Willy Brandt. Brandt is also the last name of the female CIA operative.
All of the outdoor and tram scenes were filmed in Brussels, even though several parts of the film are situated in Antwerp. The traffic signs are in two languages and the tram is of the MIVB/STIB the local public transport service.
The aerial photo in the beginning that says "Antwerpen Belgium" is in fact apicture of the city of Mechelen, with the Sint-Rombouts Belltower and it's Cathedral
Lead actor Aaron Eckhart previously starred with Ben Affleck in a similar-plot flick called Paycheck (2003) where the main protagonist's job was to reverse engineer tech and then his digital existence was nefariously erased. Except in Paycheck, Eckhart's character was the one doing the double-crossing.
Georgie Henley auditioned for the role of Amy.