Simon Bird (Will McKenzie), James Buckley (Jay Cartwright) , Blake Harrison (Neil Sutherland) and Joe Thomas (Simon Cooper) have promised viewers that they will be both laughing and crying during the movie.
Asked by Geoff Lloyd on Absolute Radio if the film is like a long episode of the sitcom, Harrison replied: "I think there is more to it than that.
"The thing is, when you're doing like a 20-odd minute sitcom, and also with our kind of series, the way we do things, we don't necessarily have an arc throughout the series so every episode kind of stands alone, and with the film obviously you've got 90-odd minutes so you have to put in a lot more of an arc than you would in a 22 minute episode... also there's more, I think you see more of the actual depths of friendship between these guys and how much they really actually do rely on each other."
Harrison added that he believes viewers will experience a range of emotions during the movie.
He said: "I think there could be a bit of both, yeah, bit of laughing and crying at the same time."
When asked if they can personally guarantee a refund to those who enjoy the show but don't enjoy the film, Buckley quipped: "I won't be refunding anyone money, by the time you leave the theatre you'll realise this was just a massive trick.
"No, it's great, it's a really nice film, and if you like the series then you should like the film because it's got us four in it doing what we do, just on a bigger screen and with a more interesting story, and it's bigger and better."
The question was asked after Tom Hanks hit the headlines earlier this week by reportedly refunding a pair of unhappy Larry Crowne viewers.
Watch Digital Spy chat to the stars of The Inbetweeners Movie below: