Graham Linehan was inspired to create the series after a PC tech with questionable interpersonal skills paid a house call.

Richard Ayoade reprised his role as Moss in The IT Crowd (2006). NBC ordered a full season and even began promoting the series for its 2007-2008 season. Though several episodes had been scripted, NBC chairman Ben Silverman had the show canceled and only the pilot was ever filmed. It is readily available online.

Noel Fielding appeared in only one episode of the third season because of schedule conflicts with The Mighty Boosh (2003). Richmond's long absence was explained as having scurvy.

A fifth series was planned but never came to light. The IT Crowd: The Internet Is Coming (2013) was made instead.

Graham Linehan's inspiration for Richmond was the sight of two Goths intently marking up their scorecards on a crazy golf course.

The show has garnered an extensive cult following among IT professionals. They've found many aspects of the show true to life. The IT "office" is located in a dingy section of the basement, usually filled with a random assortment of equipment scattered about in varying states of repair. The staff are frustrated trying to explain simple computer concepts. They play IT-related practical jokes on each other and users alike. They frequently have to deal with management that has little idea what the department really does or how much work they perform.

The show never reveals what Reynholm Industries makes. Roy and Moss's remarks to colleagues suggest "electronic machines."

Graham Linehan, the show's writer, makes numerous cameo appearances, including a mariachi, a Soviet smoker, and a mystic in the desert.

Channel 4 put the episodes online one week before they were aired on TV.

On the UK DVD release, one of the subtitle options is '1337' or 'leet' speak, a language of slang predominantly used by hackers.

The exterior shots of Reynholm Industries are News International, Thomas Moore Square London.

Moss has a picture of the Flying Spaghetti Monster on his wall.

Moss is a fan of Countdown, goes on the show and Rachel Riley is a guest in that episode. Richard Ayoade has also been on Countdown in real life.

Christopher Morris, who plays Matt Berry's character's father, is only 8 years older than him.

The antique Commodore PET computer, seen sitting on a shelf in the background of Roy and Moss's office is a genuine piece of I.T. history. These computers, made by Commodore Business Machines of the USA were some of the very first personal computers ever made for the mass market. They were 8 bit machines based around the MOS 6502 microprocessor, used their own version of BASIC, developed for them by the then fledgling Microsoft corporation and had a monochrome display. They were sophisticated computers for their day (in production from 1977-1982) and working models now fetch significant prices on eBay, often costing thousands of dollars. This Pet appears to be the 2001 model and was popular worldwide in both businesses and schools in the late 1970s/early 1980s.

Moss's surname is not a random name but an inside joke for computer geeks as it is a play on MOS Technology, one of the early microprocessor chip manufacturers whose 6502 chip was used in early 1980s machines such as the Commodore 4, BBC micro, Apple IIe and Atari video games systems.

The blue box with a black front on the shelving behind Moss is actually an Altair 8800, a very early microcomputer launched in 1975 that was programmed through a switch input (in the days before keyboards became the norm). Also on the rack is what appears to be a Sord M5 (in the brown and cream casing). This was a home computer released in the UK in 1983 but it failed to gain any traction there due to Commodore, Sinclair and Acorn being the market leaders at the time.

Chris O'Dowd and Katherine Parkinson also worked together on Doc Martin: On the Edge (2006) and The Boat That Rocked (2009)

The bleeping out of most profanities is intentional. According to Graham Linehan, he wanted to spare parents awkward situations if they watched this show with their kids, as they likely would've had to explain certain cuss words to them they didn't understand.

Jen appears outside Bill's window in the rain saying "Let me in!" after he thinks she is dead. This is likely a reference to the 1847 novel, Wuthering Heights, where a similar situation takes place. Many British programs have adapted this novel for TV.