The group rose to fame by starring in their own BBC television series, Miami 7, in 1999. Over the five years they were together, S Club 7 had four UK No.1 singles, one UK No.1 album, a string of hits throughout Europe, including a top-ten single in the United States, Asia, Latin America, and Africa. They recorded a total of four studio albums, released eleven singles and went on to sell over fourteen million albums worldwide. Their first album, S Club, had a strong 1990s pop sound, similar to many artists of their time. Through the course of their career, their musical approach changed to a more dance and R&B sound, which is heard mostly in their final album, Seeing Double. S Club 7 won two Brit Awards – in 2000 for British breakthrough act and in 2002 for best British single. In 2001, the group earned the Record of the Year award. Group member Paul Cattermole departed from the group in 2002, and the group changed its name from S Club 7 to simply S Club. On 21 April 2003, during a live on-stage performance, S Club announced that they were to disband.

Between 2004 and 2006 McIntosh tried to sign with some labels as solo artist, but failed. In 2006, he starred in an MTV reality show called Totally Boyband. Other people starring were members of disbanded groups. He became part of a boyband, Upper Street made up of ex-boyband members. The groups that each member was from were 911, Steps, Another Level and New Kids on the Block. They released the single “The One” on 23 October 2006, but it was not a commercial success, reaching #35 on the UK Singles Chart and the band had split up after confrontation with their record company. Also in 2006, was also a competitor in Sport Relief, boxing against Jack Osbourne.

In 2008, McIntosh and S Club 7 members Jo O’Meara and Paul Cattermole formed the S Club 3 and performed in various nightclubs and universities in the United Kingdom and Australia. McIntosh released his debut solo single “No Regrets (Who We Are)” in 2010 as City Boy. He also uploaded several songs to his SoundCloud account, but no new single was officially released. In 2014, S Club 7 announced their plans for an arena reunion tour, promptly entitled Bring It All Back 2015, which toured the UK in May 2015.