|Teaser from the band's new music video "Kiss You"|
A source told The Sun newspaper: "It's a really clever contract that the boys have signed up to. It means they have a real incentive to tough it out and stick together.
"The formal length is for 36 months and an album a year - but the clever part is they get the big pay day after the three years. If one of them walks away before then, then all five miss out on the money.
"They don't miss out on a few quid either, we are talking millions. They all get on really well, but it would be the kind of deal that would see them through the worst aggro possible."
Since forming in 2010 after failing to get through as solo artists on the UK edition of 'The X Factor', the group have enjoyed huge worldwide success and both their albums, 'Up All Night' and 'Take Me Home' topped the charts in several countries including the UK, America and Australia.