There is a specific Form to be filled in for permit applications (Form ‘N’). For private flights give one day notice.
Less than four commercial flights a month, give three working days and more than four, give two weeks notice.
When sending your application put in Entry/Exit points including the expected date and time at each point as well as full ATC Routing.
You need to contact us for overfly permits (must be done via AFTN or SITA).