Twitter category vote - everything you need to know!

For the first time in X Factor history, viewers can vote via hashtag on Twitter to determine which of the Judges is allocated each of the four categories – the Girls, Boys, Groups and Overs.

Tweet a hashtag with the name of the judge followed by the category you would like to see them mentor.

Voting will open as announced during the broadcast of the Programme on Saturday, 29 August 2015.

The X Factor is back! Here's our 5 top moments...

The X Factor officially made its return to our Saturday night and what a way to kick off the new series with some new Judges, new Hosts and of course, some incredible talent.

With Simon Cowell setting new Hosts Olly Murs and Caroline Flack the Mission Impossible task of finding the next big thing - complete with a surprise appearance from Wagner - to Si realising that Nick Grimshaw was not Louis Walsh, it was clear from the start it was going to be a show to remember.

Here’s our five top moments…