The IT Crowd is set in the offices of Reynholm Industries, a fictitious British corporation in central London. It focuses on the shenanigans of the three-strong IT support team located in a dingy, untidy and unkempt basement - a stark contrast to the shining modern architecture and stunning London views enjoyed by the rest of the organisation.

Moss and Roy, the two technicians, are portrayed as socially inept geeks. Despite the company's utter dependence on their services, they are despised by the rest of the staff. Roy's exasperation is reflected in his support techniques of ignoring the phone in the hope it will stop ringing, and using reel-to-reel tape recordings of stock IT suggestions ("Have you tried turning it off and on again?" and "Is it definitely plugged in?"). Moss's wide and intricate knowledge of all things technical is reflected in his extremely accurate yet utterly indecipherable suggestions, while demonstrating a complete inability to deal with practical problems like extinguishing fires and removing spiders.

Jen, the newest member of the team, is hopelessly non-technical, despite claiming on her CV that she has "a lot of experience with computers". As Denholm, the company boss, is equally tech-illiterate, he's convinced by Jen's interview bluffing and appoints her head of the I.T. department. Her official title is "relationship manager", yet her attempts at bridging the gulf between the technicians and the business generally have the opposite effect, landing Jen in situations just as ludicrous as those of her team-mates.