Contestants are asked to make a video of their act and upload it YouTube. The best videos will be added to a shortlist of 50 acts, which can be viewed on the site.
Twenty candidates will then be selected to go on TV to perform in front of the panel of judges, which will include David Hasselhoff, Michael McIntyre and Amanda Holden.
Last year's 'Britain's Got Talent' final, where the gymnastic group Spellbound were crowned winners, had a peak audience of 15 million viewers.
ITV has a new agreement with FremantleMedia and Simon Cowell's Syco Entertainment, which secures 'Britain's Got Talent' and 'The X Factor' for the network until 2013.