The band have an enthusiastic following who they refer to as their "Collaborators" and famous fans include Jade Thirlwall from Little Mix. Their debut album Stars was released on 18 August 2014 and debuted at number one in the UK.
Collabro formed in January 2014. Pagan and Lambert knew one another already, and used social media to find three additional singers to complete the band's line-up. Pagan and Lambert held auditions where they found Auger and Redgrave. They found Hadfield on YouTube singing "Bring Him Home". They sang together for the first time at the Miller pub in London Bridge. It was not long after this that they decided to audition for Britain's Got Talent, as they had 'nothing to lose'.
In February 2014, only a month after forming, Collabro auditioned in London for the eighth series of Britain's Got Talent. They received a standing ovation from both the audience and judges Simon Cowell, Amanda Holden, Alesha Dixon and David Walliams for their rendition of the song "Stars" from the musical Les Misérables. The judges were initially seen to have low expectations due to their styling and the fact that they had only been together for a month at the time. Cowell claimed that "Britain really has got talent" (a comment he repeated in the live semi-final) and they received a unanimous "yes" verdict from the judging panel, with Cowell also describing their performance as a "hit record", while Holden was reduced to tears.
On 25 May, it was announced that the band had been chosen by the judges to progress to the live semi-finals. They competed in the first semi-final on 26 May, performing the song "Bring Him Home" from Les Misérables. The performance was praised by all four judges, again receiving a standing ovation, and they received the highest number of votes from the public (receiving 62.3% of the total votes cast), ensuring their automatic progression to the final.
During the live final on 7 June, Collabro performed a different arrangement of their audition song "Stars" for which they received 26.5% of the vote, winning the competition by a wide margin.
It was confirmed on 12 June 2014 that Collabro had signed a record deal with Cowell's record label Syco Music and would be releasing their debut album on 28 July. On 17 June, they announced that they would be going on their first ever tour, along with runner-up Lucy Kay, in 2015.
The group's debut album Stars, which includes cover versions of songs such as "All of Me" and "Let It Go", was released on 18 August and debuted at number one on the UK Albums Chart. On 31 October, it was announced that the album would be re-released as . The re-released version features the seasonal "White Christmas" and "Have Yourself a Merry Little Christmas" as well as "Falling Slowly" from the musical Once and "Say Something".
The group announced it signed a record deal with USA's Sony Masterworks for £1,000,000. They will have a US release sometime this summer.