This week's guest judge is Katy Perry. The auditions start in Dublin where group Temple Fire fail to impress the judges. After more dreadful auditions Stephen Concannon and Sadbh O'Donnell manage to make it through after impressing all the judges except Simon. When 18 year old Rebecca Creighton performs though she manages to impress all the judges and sales through to the next stage of the competition. 50 year old Mary Byrne also manages to impress both the judges and audience and makes it through to the next stage of the competition. The judges are then subjected to more awful auditions when the auditions return to London. Boy band Reason manage to impress the judges though with their version of one of Cheryl's songs and make it through. Anastasia Baker who made it through to the judges house's two years ago returns to give it another shot. Simon isn't impressed by her though and asks her to sing another song. After performing again all the judges decide to put her through.
Each X Factor judge is in charge of a different section of singers on the show. The judges do not know what section of the competition they will be in charge of until the audition process has finished. Each judge then has to pick four acts to take forward to the live section of the show. Each week the two acts with the lowest amount of public votes have to sing again in a final showdown after which the judges decide who should be eliminated. Once there are only five acts left remaining it becomes left to the public to decide who should go.