Maurice Moss - Richard Ayoade: Maurice Moss (Age 32, although his online dating profile seems to assert it is 22) is a stereotypical computer nerd, and displays characteristics typical of nerd behaviour. The humour in his character is derived from his socially ignorant comments and his intricate and detailed knowledge of specialised technical subjects, including Chemistry and Electrical Engineering. He lives with his mother. Both he and Roy feel they never get the credit they deserve in the company. They also show little interest in anything related to sport, as seen in "Fifty Fifty" when asked about a prominent sports match that had been on television the previous night, neither of them knew what had happened.

Jen Barber - Katherine Parkinson: Jen is a woman who enters the department in episode one as a new starter, placed there seemingly at random by boss Reynholm, despite her lack of technical or technology management experience. Although originally intended to be the Head of Department, her role was changed to that of "Relationship Manager" due to her ability to converse with other employees within the company. She has admitted to a propensity for telling lies in order to further her own goals, as evidenced by her current occupation as a member of the IT support team. She is easily excited by stereotypical female pursuits such as shoes and men. During the second season we learn that she had been quite a heavy smoker several years previously; she took this habit up again, but quit when she realised that due to anti-smoking laws she was facing social isolation.

Roy - Chris O'Dowd: Roy is a laid back, lazy, Irish IT engineer who goes to great lengths to avoid performing his role within the organisation. He constantly eats junk food and has a low regard for his career in technology, despite signs that he is more than capable. He is a big fan of comics and often reads them when he is supposed to be working. His work attire is very casual compared to his colleagues; he wears a new geek-related t-shirt in every episode. Before becoming an IT consultant, he held a job as a waiter, during which time he would carry the food of rude customers in his trousers until he served it to them. He often attempts to attract women by methods such as pretending to be a "bastard" because he believes that that is what women want. He is rarely successful, but still has better social skills than Moss. When angry, upset or worried, his voice adopts a notably higher pitch and trembles significantly.