[1] Around over 20,000 applications were made by potential participants seeking to take part on the programme,[2] with the fourth series being the only one to date to feature more than two finalists moving on beyond the Interviews stage.

Sixteen candidates took part in the fourth series,[3] with Lee McQueen becoming the overall winner.

The number received by production staff reached a high of around 20,000,[2] leading to auditions and interviews being conducted regionally across London, Glasgow, Manchester and Bristol during the first two weeks of July, in order to assess each potential participant and narrow down the final line-up for the fourth series.

Once the sixteen candidates for this series were finalised, filming of episodes took place between September and October 2007.

Although no major changes were made to the programme's format, the fourth series saw the introduction of another of Alan Sugar's close business associates, Karren Brady, as a fourth member of the interviewing panel, prior to her eventual role after the following series.