The X Factor is a British television music competition to find new singing talent. The twelfth series began airing on ITV on 29 August 2015 and ended on 13 December 2015. The judges were Simon Cowell, Cheryl Fernandez-Versini, who returned for their respective ninth and fifth series as judges, series 9 guest judge and former The Voice UK coach Rita Ora, and BBC Radio 1 DJ Nick Grimshaw, with Grimshaw and Ora replacing Louis Walsh, the only judge who had been on the show from its inception in 2004, and Mel B. It was presented by Caroline Flack and Olly Murs, who had both previously co-presented spin-off show The Xtra Factor on ITV2 and replaced Dermot O'Leary, who left after eight series. Rochelle Humes and Melvin Odoom presented The Xtra Factor, replacing Sarah-Jane Crawford. Louisa Johnson was announced as the winner on 13 December 2015, making Ora the winning mentor.
 In March 2015, Simon Cowell was confirmed to return as a judge for the twelfth series, his ninth on the show. In April 2015, Louis Walsh cited his desire to quit the show and return to management, and that it would take serious thought for him to return for series 12. He also revealed that he was in the dark about whom Cowell had the intentions of bringing onto the panel. On 14 May 2015, Walsh confirmed his exit from the show after 11 series on the judging panel, stating, "The truth is I've done it for 11 years; I never thought I would even be on TV for four or five. To get 10 was great, to get 11 was amazing – I'm not hanging around for them this year." He later continued, "But I wasn't sacked, I haven't been hired and I'm not hanging around." On 16 June, Cheryl Fernandez-Versini was confirmed to be returning for her fifth series followed by new judges, series 9 guest judge and The Voice UK coach Rita Ora, and BBC Radio 1 DJ Nick Grimshaw, replacing Mel B and Walsh, who left the show after only one series.
 On 27 March 2015, Dermot O'Leary announced that he was quitting the show, after eight series, to pursue other projects. On 16 April, ITV confirmed that former contestant Olly Murs and Caroline Flack would take over presenting the show, having worked together as hosts before on The Xtra Factor. They became the first duo to host the show.
 On 18 June 2015, it was confirmed that The Saturdays singer Rochelle Humes and Kiss FM DJ Melvin Odoom would be the new hosts of The Xtra Factor.
 The show's announcer Peter Dickson announced his departure from the show on 28 July 2015. Dickson was later replaced by Redd Pepper for this series, who was only present for Judges' Houses. However, on 30 October 2015, Dickson confirmed that he would return to The X Factor for the live shows.
 The minimum age this year was increased back to 16, after being lowered to 14 in the previous series.
 In addition to the producers' auditions, the "Mobile Audition Tour" took place up and down the UK and Ireland throughout March and April. Auditions ran between 30 March and 23 May 2015, and visited Aberdeen, Skegness, Bradford, Huddersfield, Dundee, Sheffield, Peterborough, Northampton, Stirling, Cambridge, Middlesbrough, Nottingham, Scarborough, Norwich, Leicester, Ipswich, Coventry, York, Kingston upon Hull, Oxford, Chelmsford, Berkshire, Hertfordshire, Southend-on-Sea, Belfast, Bangor, Southampton, Isle of Man, Swansea, Blackpool, Bournemouth, Carlisle, Brighton, Truro, Isle of Wight, Wigan, Plymouth, Broadstairs, Margate, Stoke-on-Trent, Exeter, Essex and Yeovil.
 Producers auditions commenced on 8 April in Dublin and ended on 7 June in London.
 This series, the judges only visited Manchester (EventCity) and London (The SSE Arena, Wembley) on the audition tour, rather than going all around the UK as in previous series. The auditions were originally scheduled to begin in Manchester on 6 July; however, following the death of Cowell's mother on 5 July, the first two days of auditions were postponed to 8 July. As a result, a new day of auditions was announced for 9 July, but this last-minute addition meant that both Ora and Flack were absent due to prior commitments, resulting in just three judges that day and Murs having to host solo. The first day of London auditions were scheduled to be recorded on 14 July, but were cancelled due to the aforementioned bereavement. Flack was also absent from filming on 15 July due to her filming the Love Island final in Spain. Grimshaw had to leave the evening sessions (15, 16, 17, 19, 20 July) of auditions early due to the session over-running and his contract obligated him to have a certain amount of rest between finishing filming and being on BBC Radio 1 the following morning. Filming was delayed on 20 July due to Fernandez-Versini suffering a burns injury to her foot after stepping on some hair tongs. Cowell was absent from the first session on 17 July due to illness. Ora was again absent from filming on 22 July, due to performing a prearranged gig in Italy.[citation needed]
 Notable returning auditionees included Havva Rebke, who reached bootcamp in series 9; Monica Michael, who was controversially eliminated during the six chair challenge in series 11; and Rumour Has It, who reached judges' houses in series 11 as an unnamed girl group created by the judges. Other notable auditionees included MJ Mytton Sanneh and Mitchell Zhangazha members of boy band Tribe previously finished third in the fifth series of Britain’s Got Talent as members of New Bounce.
 Bootcamp took place from 27 to 31 July, and was recorded at The Grove Hotel, Watford, having taken place at The SSE Arena, Wembley every other series. The first challenge of bootcamp was to perform in groups of five acts, with a mix of at least three categories in each group, and perform a song from a list. The judges would decide immediately after each performance which of the 180 acts would pass the challenge and which would be eliminated. For the second challenge of bootcamp, the 93 successful acts were to perform a solo performance to the judges, who gave little or no feedback to them. At the end of the challenge, the judges decided on who would be successful and who would be eliminated. Grimshaw was absent from the second day of the challenge due to his commitments with BBC Radio 1, although partially assisted Cowell, Fernandez-Versini and Ora with their decisions via Skype video link. The 64 acts that passed through this stage went on to face the six-chair challenge. It was reported that the standard of auditions were so high that acts who got a "yes" from all four judges were not necessarily guaranteed a place at bootcamp.
 For the first time in X Factor history, viewers voted via hashtags on Twitter to determine which of the judges was allocated each of the four categories (for example, #SimonBoys or #RitaGroups). The judges learnt the result during the six-seat challenge. Ora was in charge of the Girls, Cowell was assigned the Over 27s, Fernandez-Versini had the Groups and Grimshaw looked after the Boys.
 Bootcamp aired over two episodes on 20 and 27 September.
 The six-chair challenge took place on 1 and 2 September, at The SSE Arena, Wembley. 64 acts faced the six-chair challenge, with 16 in the Girls category, 16 in the Boys, 17 in the Over 27s, and 15 in the Groups. The challenge was broadcast on 4, 11 and 18 October. At the start of the challenge, the judges discovered which categories they would mentor: Ora was given the Girls, Cowell was given Over 27s, Fernandez-Versini was given the Groups and Grimshaw was given the Boys.
 Tom Bleasby was originally put through, but it was reported on 12 October that he had withdrawn for personal reasons. On 15 October, it was announced that Mason Noise would replace Bleasby at Judges' Houses.
 On 20 October, it was revealed that all the groups would undergo name changes due to copyright reasons. The new names were revealed as 4th Impact (4th Power), Alien Uncovered (Alien), BEKLN Mile (BEKLN), Melody Stone (Silver Tone), New Kings Order (The First Kings) and Reggie 'n' Bollie (Menn On Point)
 The X Factor resumed its usual Saturday and Sunday night slots for judges' houses, taking place over one weekend (24–25 October). Murs and Flack did not appear at judges' houses, but filmed from the studio. Judges' houses was planned to be broadcast fully live, and recorded back-to-back, but on 15 September, it was announced that this would not happen as it would cause logistical problems. Instead, the judges' houses performances were pre-recorded in the scheduled destinations, with all of the contestants who made it to that stage of the competition brought to London afterwards to watch the performances and find out if they had made it through to the live shows during a live broadcast. This was the only portion of judges' houses that was broadcast live.
 On 1 October, the guest judges for the judges' houses stage were revealed. Meghan Trainor assisted Ora in Los Angeles, Cowell's assistant was Louis Tomlinson, joining him in the Loire Valley, Franc, Fernandez-Versini was joined by Jess Glynne in Rome and Mark Ronson helped Grimshaw in the Cotswolds.
 Girls:
 Boys:
 Groups:
 Over 27s:
 After being eliminated, Monica Michael was reinstated as a wildcard before the live shows.
 Key:
 This year, there were seven weeks of live shows instead of the usual ten. ITV were contractually obliged to show all of Home Nation's Rugby World Cup games in October, some of which take place during The X Factor‍'s Saturday night slot. One option that was considered was to air a bumper show on Sunday nights on these weekends, while some reports suggested that the live shows would run for a fewer number of weeks, launching after the World Cup. In fact, bootcamp aired during the Rugby World Cup and the live shows began on 31 October and continued until 13 December, airing every Saturday and Sunday night in the regular timeslots. Due to the omission of three live shows and the introduction of the wildcard act, the first four live shows were all double eliminations. The Xtra Factor moved its Saturday episode to Thursdays, being broadcast before the live shows, starting on 29 October. with the Sunday episode remaining the same. The Saturday edition of The Xtra Factor was reinstated for the final alongside the Thursday and Sunday editions.
 The performance shows took place on Saturday night with the results show airing on Sunday night. Each results show featured guest performances, with some guests performing during the main performance show. The X Factor series 11 winner Ben Haenow performed on the first live show on 31 October, whilst series 8 winners Little Mix and Ellie Goulding performed on the first live results show on 1 November.[citation needed] Series 11 runner up Fleur East and CeeLo Green performed on the second live results show on 8 November,[citation needed] whilst Jess Glynne and series 7 contestants One Direction performed during the third live results show on 15 November. The fourth live show featured a performance from Rudimental featuring Ed Sheeran, while Nathan Sykes and Murs performed on the fourth live results show on 22 November. The quarter-final results show on 29 November featured performances from Carrie Underwood, and Sigma and Ora. Jason Derulo and Sia performed during the semi-final results on 6 December. The live final on 12 December featured duets from Leona Lewis and Ben Haenow, and Little Mix and Fleur East. and a performance from Rod Stewart. The results show on 13 December featured performances from One Direction, Coldplay and Adele.
 This week's results show featured a double elimination. The three acts with the fewest votes were announced as the bottom three and the act with the fewest public votes was then automatically eliminated. The remaining two acts then performed in the final showdown for the judges' votes.
 However, voting statistics revealed that Alien Uncovered received more votes than Weathers which meant that if Cowell sent the result to deadlock, Alien Uncovered would have been saved.
 This week's results show featured a double elimination. The three acts with the fewest votes were announced as the bottom three and the act with the fewest public votes was then automatically eliminated. The remaining two acts then performed in the final showdown for the judges' votes.
 With the acts in the sing-off receiving two votes each, the result went to deadlock and reverted to the earlier public vote. Seann Miley Moore was eliminated as the act with the fewest public votes.
 As a mark of respect following the November 2015 Paris attacks it was announced that Lauren Murray and Monica Michael would change their songs. Murray was due to perform "Licence to Kill" and Michael would have performed "Bang Bang (My Baby Shot Me Down)".
 At the beginning of the results show, it was announced that the acts who made it through this week would be on The X Factor Live Tour 2016 (Seann Miley Moore was later given a place on the tour).
 This week's results show featured a double elimination. The three acts with the fewest votes were announced as the bottom three and the act with the fewest public votes was automatically eliminated. The remaining two acts then performed in the final showdown for the judges' votes.
 With the acts in the sing-off receiving two votes each, the result went to deadlock and reverted to the earlier public vote. Monica Michael was eliminated as the act with the fewest public votes.
 This week featured a double elimination. The first was on Saturday night, when the act with the fewest votes so far was immediately eliminated. Following this the voting was re-opened, and the two acts with the fewest votes on Sunday's results show then performed in the sing-off.
 This week was the first single elimination of the series.
The finalists performed two songs this week; one picked by the mentors and one picked by the viewers. The public voted on Twitter for the songs the contestants will perform. Each act had a choice of three songs and viewers could tweet a hashtag for the song they wanted them to sing. Voting opened at the end of the fourth live results show, and closed at midnight that night.
 With the acts in the sing-off receiving two votes each, the result went deadlock and reverted to the earlier public vote. 4th Impact were eliminated as the act with the fewest public votes.
 With the acts in the sing-off receiving two votes each, the result went to deadlock and reverted to the earlier public vote. Lauren Murray was eliminated as the act with the fewest public votes.
 ^1  The acts performed individual songs as they were introduced at the start of the show. Chesterman performed "In the Air Tonight", Johnson performed "Fighter" and Reggie 'n' Bollie performed "Jump", although these were not considered to be their first performances.
 Ché Chesterman received the fewest public votes and was automatically eliminated.
 1 Includes advert breaks
2 The ITV+1 figure for this episode is unavailable as it was outside the top 10 programmes of the week on BARB.
3 The ratings over a 7-day period, including the original broadcast and streaming through ITV Player.
4 The rank for the ITV broadcast, compared with all channels for that week, from Monday to Sunday.
5 The ITV HD figure for this episode is unavailable as it was outside the top 10 programmes of the week on BARB.
6 The average figure for ITV HD includes only the episodes with figures available.
7 The average figure for ITV+1 includes only the episodes with figures available.
 It was reported that before bootcamp, some contestants who were given three or four "yes" votes from the judges were sent emails from the producers of the show saying that they would not be attending bootcamp due to limited places and a higher standard of auditions. One contestant who received such an email said, "I feel X Factor needs to be shamed for this shocking incident. They are playing with people's lives." A spokesperson for the show said this was "kinder and fairer than an immediate 'cull' of singers on arrival at bootcamp, which has happened in previous series."
 During the six-seat challenge, after performing for his mentor Grimshaw, Noise complained that his audition was only broadcast for 47 seconds while other contestants were featured for up to 10 minutes. Cowell responded by saying "You should feel lucky to be on this show. Why don't you shut up?" and called Noise an "arsehole". Noise was booed by the crowd before walking off the stage. Noise later told the Daily Mirror: "[Cowell] lost control and it was uncalled for. Especially as all I was doing was saying an opinion. I think that no one has ever questioned him before and no one has questioned the format of the show. Something needs to change on that show. Listen to the kids, at the end of the day I have a lot of support on Twitter."
 On 12 October, Tom Bleasby had withdrawn from the show and consequently, there was a spare place at judges' houses. On 15 October, Grimshaw announced that Noise would replace Bleasby at judges' houses.
 Presenters Flack and Murs were criticised throughout the series. Flack's absence from several auditions caused confusion and their lack of chemistry was criticised, with a source from the show saying, "Bosses have been aware of the criticism aimed at Olly and Caroline over their lack of chemistry. They were expected to inject some fun and energy but that has yet to be seen. We've seen this year's line-up undertake a big shake-up and Olly and Caroline were considered to be a safe bet." It was also stated that Flack's other commitments were discussed beforehand. A spokesperson said: "Olly and Caroline have been great additions to the show, We're very happy with them and look forward to them being centre stage when presenting on the live shows at the end of the month."
 In week 3, Murs apologised after claiming that Michael had been eliminated when in fact the result went to deadlock and yet to be revealed; in any case, Michael was revealed afterwards to have received the fewest public votes and voted out. Murs said: "I apologise to everyone tonight I made a massive f—k up at the end. It was so tense!! I'm still learning & hope that never happens again!" Isabel Mohan from The Daily Telegraph said, "We were always dreading Flack and Murs taking over from Dermot O'Leary—we knew they wouldn't be able to hack it live on primetime telly. Dermot could build up tension. Dermot could read autocues. Dermot could speak properly with no lazy talk of 'the bottom free'. And, most of all, Dermot didn't tell people they'd been voted off before he was supposed to! [...] What an absolute shambles." O'Leary supported Murs on Twitter, saying it "Happens to us all" and "live TV is a tricky old beast at times."