Preparation costs Costs incurred for the development of the operation. Are only eligible for approved operations and only if they were incurred on or after the date of eligibility of the specific INTERREG IIIC Programme to which the Application Form has been submitted (for North – 5 October 2001, East – 5 November 2001, South – 6 December 2001, West – 12 October 2001), and before the date on which the Application Form has been submitted.