The remainder will be sold to residents living within a 15-mile radius of the festival site.
Mendip councillors agreed to increase the crowd limit after being told that the proceeds would be donated to the tsunami appeal.
It is rumoured that acts like Kylie Minogue, Rufus Wainwright, Brian Wilson, Ian Brown, Lauren Hill, Van Morrison, Garbage, The Bravery, Futureheads, Soulwax, Cake, Thirteen Senses, Jools Holland, Bright Eyes, Brendan Benson and The Faint will play.