A permit determines a player's limits on various aspects of the game. There are currently two types of permits in the game: a standard permit and a pro permit.
Standard Permit Edit
Players are granted a standard permit when they start the game.
Pro Permit Edit
The Pro Permit can be purchased for $7.99. Prior to update 1.10, it costed $4.99 (£4.09).
A pro permit allows a player to construct up to 10 silos and makes your silos high quality. The pro permit also allows a player to use up to 5 boosts simultaneously. The pro permit can be purchased in the shop by tapping the purple shop button in the top right of the screen and then tapping the "pro permit" button.