The group's debut album Right Now was released in October 2000 and charted at number 39 in the United Kingdom. After five top ten singles, original member Kerry Katona quit – four weeks before Whole Again reached number one in the UK Singles Chart – and was replaced by former Precious singer Jenny Frost. Whole Again became the group's most successful single, staying at number one for four weeks in the UK and six weeks in Germany, and reaching number one in many other territories; in Britain, it was the 13th best-selling single of the 2000s.
The group re-released their debut album, with some tracks re-recorded with Frost's vocals: it peaked at number one in the UK and was certified double platinum after selling over 600,000 copies. Between 2002 and 2004, the group released a further two studio albums, Feels So Good and Ladies Night, and a greatest hits album before announcing a break following their 2004 tour.
To date the group have had three UK number-one singles: Whole Again, the fourth best-selling song of all time by a girl group in the UK; Eternal Flame, a song originally recorded by The Bangles and The Tide Is High (Get the Feeling), a song originally recorded by The Paragons.They have sold over 10 million records worldwide.
After making sporadic appearances in 2006 and 2008, it was announced that McClarnon, Hamilton, and Katona would reunite for the ITV2 series The Big Reunion, alongside five other pop groups of their time: B*Witched,Five,Liberty X,Honeyz and 911. Frost was unable to take part in the comeback because of her pregnancy, but Hamilton has since said that Frost would be welcomed back if she wanted to rejoin the group in the future. Katona left the group for a second time in December 2017 leaving the group as a duo.