A permission letter is written to request for a “legal authorization” to do something. In the course of writing the letter, it is required that you specify the nature of what you need permission for. It might be permission to take leave from work, permission to take custody of a child, permission to use a place for an event, permission to use a person’s property. You must also state the reason why you are requesting for that particular permission. In the concluding part, you state that you would appreciate it if your permission is granted.