An application for a variation in the premises licence was granted by Derbyshire Dales District Council and takes the capacity from 29,999 to 39,999.
Jason Oakley, managing director of Y Not, said the application was submitted in a bid to get the festival back to being as good as it could be.
He said that capacity at the last festival in 2020 was dropped to 29,999 because “projected sales were not warranting the size of the licence so decided to scale it back to reflect this."
Jason added: “"Sales have improved and tickets are going well this year so wanted to have the option to sell to our site capacity again. It also encompasses numbers of ancilliary staff as well as customers and we are really going for a strong, operationally robust show this year so there are more staff than ever on site, literally thousands.
“We want to have the option to sell up to 30,000 tickets again if possible (including staff this would mean we would have well over that number of people on site).
"Tickets are really going well and we could even be heading for a sell-out event as they seem to be selling faster and faster as the summer approaches."
Commenting on Y Not’s premises licence application, a council spokesman said: “The consultation period ended on 11 March. No objections were received and therefore the varied licence is deemed granted. The increase has also been discussed through the Derbyshire Events Safety Advisory Group, so all ‘regulatory’ partners are aware of the increase and this is being factored into planning for the event."
The spokesman added that fees for premises licences are set at national level and are currently £8,000 for an event with a capacity of 20,000 to 20,999 and £16,000 for an event with a capacity of 30,000 to 39,999.